Solidarity and ambivalence: comparing two perspectives on intergenerational relations using longitudinal panel data.

Science.gov (United States)

Hogerbrugge, Martijn J A; Komter, Aafke E

2012-05-01

Research on family relations has extensively used the intergenerational solidarity model proposed by Bengtson and colleagues. Recently, the relevance of this model for explaining changes in family relations has been questioned, and the concept of intergenerational ambivalence has been proposed as a relevant addition to the model, supposedly acting as a catalyst, and thus serving as an explanation for changes in family relations. This study tests both the viability of the intergenerational solidarity model and the hypothesized effect of ambivalence employing longitudinal data. We use data from 2 waves of the Netherlands' Kinship Panel Study on parent-adult child relationships to estimate latent variable structural equation models. Affection, association, and support between family members are core, mutually reinforcing dimensions of solidarity. The hypothesis that ambivalence is a catalyst for change in family relations was not confirmed. Adding conflict separately revealed that it only affects the core solidarity dimensions but is itself, like normative and structural solidarity, not influenced by them. The relevance of the concept of intergenerational ambivalence for studying changes in family relations can be questioned. The viability of the intergenerational solidarity model is, however, confirmed. The concept of intergenerational ambivalence might be further explored in qualitative studies on family change.

Use of Internet panels to conduct surveys.

Science.gov (United States)

Hays, Ron D; Liu, Honghu; Kapteyn, Arie

2015-09-01

The use of Internet panels to collect survey data is increasing because it is cost-effective, enables access to large and diverse samples quickly, takes less time than traditional methods to obtain data for analysis, and the standardization of the data collection process makes studies easy to replicate. A variety of probability-based panels have been created, including Telepanel/CentERpanel, Knowledge Networks (now GFK KnowledgePanel), the American Life Panel, the Longitudinal Internet Studies for the Social Sciences panel, and the Understanding America Study panel. Despite the advantage of having a known denominator (sampling frame), the probability-based Internet panels often have low recruitment participation rates, and some have argued that there is little practical difference between opting out of a probability sample and opting into a nonprobability (convenience) Internet panel. This article provides an overview of both probability-based and convenience panels, discussing potential benefits and cautions for each method, and summarizing the approaches used to weight panel respondents in order to better represent the underlying population. Challenges of using Internet panel data are discussed, including false answers, careless responses, giving the same answer repeatedly, getting multiple surveys from the same respondent, and panelists being members of multiple panels. More is to be learned about Internet panels generally and about Web-based data collection, as well as how to evaluate data collected using mobile devices and social-media platforms.

Nonlinear panel flutter in a rarefied atmosphere - Aerodynamic shear stress effects

Science.gov (United States)

Resende, Hugo B.

1991-01-01

The panel flutter phenomenon is studied assuming free-molecule flow. This kind of analysis is relevant in the case of hypersonic flight vehicles traveling at high altitudes, especially in the leeward portion of the vehicle. In these conditions the aerodynamic shear can be expected to be considerably larger than the pressure at a given point, so that the effects of such a loading are incorporated into the structural model. This is accomplished by introducing distributed longitudinal and bending moment loads. The former can lead to buckling of the panel, with the second mode in the case of a simply-supported panel playing a important role, and becoming the dominant mode in the solution. The presence of equivalent springs in the longitudinal direction at the panel's ends also becomes of relative importance, even for the evaluation of the linear flutter parameter. Finally, the behavior of the system is studied in the presence of applied compressive forces, that is, classical buckling.

Effort-reward imbalance and work ability: cross-sectional and longitudinal findings from the Second German Sociomedical Panel of Employees

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Bethge Matthias

2012-10-01

Full Text Available Abstract Background Although data from longitudinal studies are sparse, effort-reward imbalance (ERI seems to affect work ability. However, the potential pathway from restricted work ability to ERI must also be considered. Therefore, the aim of our study was to analyse cross-sectional and longitudinal associations between ERI and work ability and vice versa. Methods Data come from the Second German Sociomedical Panel of Employees. Logistic regression models were estimated to determine cross-sectional and longitudinal associations. The sample used to predict new cases of poor or moderate work ability was restricted to cases with good or excellent work ability at baseline. The sample used to predict new cases of ERI was restricted to persons without ERI at baseline. Results The cross-sectional analysis included 1501 full-time employed persons. The longitudinal analyses considered 600 participants with good or excellent baseline work ability and 666 participants without baseline ERI, respectively. After adjustment for socio-demographic variables, health-related behaviour and factors of the work environment, ERI was cross-sectionally associated with poor or moderate work ability (OR = 1.980; 95% CI: 1.428 to 2.747. Longitudinally, persons with ERI had 2.1 times higher odds of poor or moderate work ability after one year (OR = 2.093; 95% CI: 1.047 to 4.183. Conversely, persons with poor or moderate work ability had 2.6 times higher odds of an ERI after one year (OR = 2.573; 95% CI: 1.314 to 5.041. Conclusions Interventions that enable workers to cope with ERI or address indicators of ERI directly could promote the maintenance of work ability. Integration management programmes for persons with poor work ability should also consider their psychosocial demands.

Predicting Internet risks: a longitudinal panel study of gratifications-sought, Internet addiction symptoms, and social media use among children and adolescents

Science.gov (United States)

Leung, Louis

2014-01-01

This study used longitudinal panel survey data collected from 417 adolescents at 2 points in time 1 year apart. It examined relationships between Internet risks changes in Time 2 and social media gratifications-sought, Internet addiction symptoms, and social media use all measured at Time 1. By controlling for age, gender, education, and criterion variable scores in Internet addiction at Time 1, entertainment and instant messaging use at Time 1 significantly predicted increased Internet addiction measured at Time 2. The study also controlled for demographics and scores of criterion variables in Internet risks: targeted for harassment, privacy exposed, and pornographic or violent content consumed in Time 1. Gratifications-sought (including status-gaining, expressing opinions, and identity experimentation), Internet addiction symptoms (including withdrawal and negative life consequences), and social media use (in particular, blogs, and Facebook) significantly predicted Internet risk changes in Time 2. These findings suggest that, with their predictive power, these predictors at Time 1 could be used to identify those adolescents who are likely to develop Internet addiction symptoms and the likelihood of experiencing Internet risks based on their previous gratifications-sought, previous addiction symptoms, and their habits of social media use at Time 1. PMID:25750792

Predicting Internet risks: a longitudinal panel study of gratifications-sought, Internet addiction symptoms, and social media use among children and adolescents.

Science.gov (United States)

Leung, Louis

2014-01-01

This study used longitudinal panel survey data collected from 417 adolescents at 2 points in time 1 year apart. It examined relationships between Internet risks changes in Time 2 and social media gratifications-sought, Internet addiction symptoms, and social media use all measured at Time 1. By controlling for age, gender, education, and criterion variable scores in Internet addiction at Time 1, entertainment and instant messaging use at Time 1 significantly predicted increased Internet addiction measured at Time 2. The study also controlled for demographics and scores of criterion variables in Internet risks: targeted for harassment, privacy exposed, and pornographic or violent content consumed in Time 1. Gratifications-sought (including status-gaining, expressing opinions, and identity experimentation), Internet addiction symptoms (including withdrawal and negative life consequences), and social media use (in particular, blogs, and Facebook) significantly predicted Internet risk changes in Time 2. These findings suggest that, with their predictive power, these predictors at Time 1 could be used to identify those adolescents who are likely to develop Internet addiction symptoms and the likelihood of experiencing Internet risks based on their previous gratifications-sought, previous addiction symptoms, and their habits of social media use at Time 1.

Optimal assignment methods in three-form planned missing data designs for longitudinal panel studies

NARCIS (Netherlands)

Jorgensen, T.D.; Rhemtulla, M.; Schoemann, A.; McPherson, B.; Wu, W.; Little, T.D.

2014-01-01

Planned missing designs are becoming increasingly popular, but because there is no consensus on how to implement them in longitudinal research, we simulated longitudinal data to distinguish between strategies of assigning items to forms and of assigning forms to participants across measurement

When Volunteering Breeds Trust – and When it Does Not A Panel Study of the Volunteering – Trust Relationship

NARCIS (Netherlands)

Bekkers, René

2006-01-01

It is a common belief that participation in voluntary associations makes citizens more trusting of others. This paper reports longitudinal analyses of volunteering and trust on the Giving in the Netherlands Panel Study (2002-2004; n=1246) refuting this belief. I find that volunteering has little

Relationship between Mobile Phone Addiction and the Incidence of Poor and Short Sleep among Korean Adolescents: a Longitudinal Study of the Korean Children & Youth Panel Survey

Science.gov (United States)

2017-01-01

Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011–2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or short sleep duration in the previous year. A generalized estimating equation was used to analyze the data. High mobile phone addiction (mobile phone addiction score > 20) increased the risk of poor sleep quality but not short sleep duration. We suggest that consistent monitoring and effective intervention programs are required to prevent mobile phone addiction and improve adolescents' sleep quality. PMID:28581275

Relationship between Mobile Phone Addiction and the Incidence of Poor and Short Sleep among Korean Adolescents: a Longitudinal Study of the Korean Children & Youth Panel Survey.

Science.gov (United States)

Lee, Joo Eun; Jang, Sung In; Ju, Yeong Jun; Kim, Woorim; Lee, Hyo Jung; Park, Eun Cheol

2017-07-01

Three of ten teenagers in Korea are addicted to mobile phones. The aim of this study was to examine the relationship between mobile phone addiction and the incidence of poor sleep quality and short sleep duration in adolescents. We used longitudinal data from the Korean Children & Youth Panel Survey conducted by the National Youth Policy Institute in Korea (2011-2013). A total of 1,125 students at baseline were included in this study after excluding those who already had poor sleep quality or short sleep duration in the previous year. A generalized estimating equation was used to analyze the data. High mobile phone addiction (mobile phone addiction score > 20) increased the risk of poor sleep quality but not short sleep duration. We suggest that consistent monitoring and effective intervention programs are required to prevent mobile phone addiction and improve adolescents' sleep quality. © 2017 The Korean Academy of Medical Sciences.

Persistent work-life conflict and health satisfaction - a representative longitudinal study in Switzerland

OpenAIRE

Knecht, Michaela; Bauer, Georg F; Gutzwiller, Felix; Hämmig, Oliver

2011-01-01

Abstract Background The objectives of the present study were (1) to track work-life conflict in Switzerland during the years 2002 to 2008 and (2) to analyse the relationship between work-life conflict and health satisfaction, examining whether long-term work-life conflict leads to poor health satisfaction. Methods The study is based on a representative longitudinal database (Swiss Household Panel), covering a six-year period containing seven waves of data collection. The sample includes 1261 ...

Physical activity levels and determinants of change in young adults: a longitudinal panel study

Directory of Open Access Journals (Sweden)

Zimmermann Erwin

2010-01-01

Full Text Available Abstract Background There is growing concern about physical inactivity in adolescents and young adults. Identifying determinants that are associated with low levels of physical activity and with changes in physical activity levels will help to develop specific prevention strategies. The present study describes the prevalence and potential determinants of physical activity behavior and behavior changes of young adults. The study is based on the Swiss Household Panel (SHP, a longitudinal study assessing social changes in a representative sample of Swiss households since 1999. Methods Data is collected yearly using computer-assisted telephone interviews. Information is obtained from each household member over 14 years of age. Participants between 14 and 24 years entering the SHP between 1999 and 2006 were included (N = 3,068. "Inactive" was defined as less than 1 day/week of at least 30 minutes of moderate physical activity, "no sport" as exercising less than once a week. Age, gender, nationality, linguistic region, household income, education, membership in a sport club, reading, and Internet use were included as potential determinants of physical activity behavior and behavior change. Results In both young men and young women, the prevalence of inactivity, "no sport", and non-membership in a sport club was increasing with age. Women were less active than men of the same age. From one wave to the following, 11.1% of young men and 12.1% of young women became active, and 11.9% of men and 13.7% of women became inactive, respectively (pooled data over all eight waves. Non-membership in a sport club was the strongest predictor for "no sport" (ORmen 6.7 [4.9-8.9]; ORwomen 8.1 [5.7-11.4], but also for being inactive (OR 4.6 [3.5-6.0]; 4.6 [3.3-6.4]. Leaving a sport club (OR 7.8 [4.4-14.0]; 11.9 [5.9-24.1] and remaining non-member (OR 7.8 [4.7-12.9]; 12.4 [6.4-24.1] were the strongest predictors of becoming "no sport". Effects for becoming inactive were

Compressive Strength of Longitudinally Stiffened GRP Panels

DEFF Research Database (Denmark)

Böhme, J.; Noury, P.; Riber, Hans Jørgen

1996-01-01

A structural analysis of a cross stiffened orthotropic GRP panel subjected to uniaxial compressive loads is carried out. Analytical solutions to the buckling of such structures are proposed and validated by a finite element analysis. Both analytical and finite element approaches confirm an identi...

The Interplay among Environmental Attitudes, Pro-Environmental Behavior, Social Identity, and Pro-Environmental Institutional Climate. A Longitudinal Study

Science.gov (United States)

Prati, Gabriele; Albanesi, Cinzia; Pietrantoni, Luca

2017-01-01

By using a panel design in a sample of 298 undergraduate/master students at an Italian public university, the present study aimed to test longitudinally the interplay among environmental attitudes, pro-environmental behavior, social identity, and pro-environmental institutional climate. The relationships were tested with cross-lagged analysis…

Cultural events – does attendance improve health? Evidence from a Polish longitudinal study

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Dorota Węziak-Białowolska

2016-08-01

Full Text Available Abstract Background Although there is strong advocacy for uptake of both the arts and creative activities as determinants of individual health conditions, studies evaluating causal influence of attendance at cultural events on population health using individual population data on health are scarce. If available, results are often only of an associative nature. In this light, this study investigated causative impact of attendance at cultural events on self-reported and physical health in the Polish population. Methods Four recent waves (2009, 2011, 2013 and 2015 of the biennial longitudinal Polish household panel study, Social Diagnosis, were analysed. The data, representative for the Polish population aged over 16, with respect to age, gender, classes of place of residence and NUTS 2 regions, were collected from self-report questionnaires. Causative influence of cultural attendance on population health was established using longitudinal population representative data. To account for unobserved heterogeneity of individuals and to mitigate issues caused by omitted variables, a panel data model with a fixed effects estimator was applied. The endogeneity problem (those who enjoy good health are more likely to participate in cultural activities more frequently was circumvented by application of instrumental variables. Results Results confirmed positive association between cultural attendance and self-reported health. However, in contrast to the often suggested positive causative relationship, such a link was not confirmed by the study. Additionally, no evidence was found to corroborate a positive impact from cultural attendance on physical health. Both findings were substantiated by augmentation in the longitudinal perspective and causal link. Conclusions We showed the relation between attendance at cultural events and self-reported health could only be confirmed as associational. Therefore, this study provided little justification to encourage use

Advantages and disadvantages : longitudinal vs. repeated cross-section surveys

Science.gov (United States)

1996-06-20

The benefits of a longitudinal analysis over a repeated cross-sectional study include increased statistical power and the capability to estimate a greater range of conditional probabilities. With the Puget Sound Transportation Panel (PSTP), and any s...

Family effects on the rurality of GP's work location: a longitudinal panel study.

Science.gov (United States)

McGrail, Matthew R; Russell, Deborah J; O'Sullivan, Belinda G

2017-10-19

Reduced opportunities for children's schooling and spouse's/partner's employment are identified internationally as key barriers to general practitioners (GPs) working rurally. This paper aims to measure longitudinal associations between the rurality of GP work location and having (i) school-aged children and (ii) a spouse/partner in the workforce. Participants included 4377 GPs responding to at least two consecutive annual surveys of the Medicine in Australia: Balancing Employment and Life (MABEL) national longitudinal study between 2008 and 2014. The main outcome, GP work location, was categorised by remoteness and population size. Five sequential binary school-age groupings were defined according to whether a GP had no children, only preschool children (aged 0-4 years), at least one primary-school child (aged 5-11 years), at least one child in secondary school (aged 12-18 years), and all children older than secondary school (aged ≥ 19). Partner in the workforce was defined by whether a GP had a partner who was either currently working or looking for work, or not. Separate generalised estimating equation models, which aggregated consecutive annual observations per GP, tested associations between work location and (i) educational stages and (ii) partner employment, after adjusting for key covariates. Male GPs with children in secondary school were significantly less likely to work rurally (inclusive of > 50 000 regional centres through to the smallest rural towns of locations were not significantly associated with the educational stage of their children. Having a partner in the workforce was not associated with work location for male GPs, whereas female GPs with a partner in the workforce were significantly less likely to work in smaller rural/remote communities (location is related to key family needs which differ according to GP gender and educational stages of children. Such non-professional factors are likely to be dynamic across the GP's lifespan and

Response problems in a vacation panel study

Science.gov (United States)

Christine A. Vogt; Susan I. Stewart

2001-01-01

This paper investigates response problems encountered in a panel study of travel behavior. Though the overall response rate to the three-wave panel study was acceptable (over 60%), three types of response problems were encountered: refusal, non-response, and attrition. In a follow-up phone survey, a sample of individuals from each problem response group was questioned...

Cross-Sectional Analysis of Longitudinal Mediation Processes.

Science.gov (United States)

O'Laughlin, Kristine D; Martin, Monica J; Ferrer, Emilio

2018-01-01

Statistical mediation analysis can help to identify and explain the mechanisms behind psychological processes. Examining a set of variables for mediation effects is a ubiquitous process in the social sciences literature; however, despite evidence suggesting that cross-sectional data can misrepresent the mediation of longitudinal processes, cross-sectional analyses continue to be used in this manner. Alternative longitudinal mediation models, including those rooted in a structural equation modeling framework (cross-lagged panel, latent growth curve, and latent difference score models) are currently available and may provide a better representation of mediation processes for longitudinal data. The purpose of this paper is twofold: first, we provide a comparison of cross-sectional and longitudinal mediation models; second, we advocate using models to evaluate mediation effects that capture the temporal sequence of the process under study. Two separate empirical examples are presented to illustrate differences in the conclusions drawn from cross-sectional and longitudinal mediation analyses. Findings from these examples yielded substantial differences in interpretations between the cross-sectional and longitudinal mediation models considered here. Based on these observations, researchers should use caution when attempting to use cross-sectional data in place of longitudinal data for mediation analyses.

Ultimate uniaxial compressive strength of stiffened panel with opening under lateral pressure

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Chang-Li Yu

2015-03-01

Full Text Available This paper concentrated on the ultimate uniaxial compressive strength of stiffened panel with opening under lateral load and also studied the design-oriented formulae. For this purpose, three series of well executed experiments on longitudinal stiffened panel with rectangular opening subjected to the combined load have been selected as test models. The finite element analysis package, ABAQUS, is used for simulation with considering the large elasticplastic deflection behavior of stiffened panels. The feasibility of the numerical procedure is verified by a good agreement of experimental results and numerical results. More cases studies are executed employing nonlinear finite element method to analyze the influence of design variables on the ultimate strength of stiffened panel with opening under combined pressure. Based on data, two design formulae corresponding to different opening types are fitted, and accuracy of them is illustrated to demonstrate that they could be applied to basic design of practical engineering structure.

Emergency destruction of a panel residence building, type series 1-115

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Malakhova Anna Nikolaevna

2014-12-01

Full Text Available The co-authors consider the design solution developed for a panel residence building, type series 1-115, and provide a description of the emergency destruction of structural elements of a 9-storey panel residence building of this type (built in 1979, following a gas explosion. The overall length of the building is 86.4 m; its width is 12 m. The structural system in this building represents a longitudinal wall. Its external longitudinal walls are wade of ceramsite concrete, while its interior walls are made of concrete. Its reinforced concrete hollow slabs rest on the longitudinal load-bearing walls. The transverse walls of staircases are made of concrete blocks. The strip foundation supports the load-bearing walls of the building. The epicenter of the explosion was located in the kitchen on the eighth floor of the building. The kitchen was immediately adjacent to the staircase of the building. Partial destruction of the building followed the gas explosion. Exterior walls of its eighth and ninth floors and the attic were destroyed. Panel buildings designed in pursuance of the longitudinal structural system are more vulnerable to explosive loads compared to buildings designed to the cross-wall structural system, where bearing slabs rest on three interior walls. Thus, all slabs rest on each of the three internal walls of the building on both sides. In the buildings designed to the longitudinal wall structural system, slabs rest on the two walls, one of which is external. The article is based on the report following the inspection of the technical condition of the building, undertaken subsequent to its emergency destruction.

Experimental Investigation of Discharge Coefficient in Mesh Panel Bottom Intakes

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keivan bina

2012-04-01

Full Text Available Bottom racks is a hydraulic structure which is placed in the bed of stream through which, part of flow in the main channel is diverted. These structures have very wide application in industry, irrigation, drainage and etc. Of course much attention had been paid to the study of such structures, but characteristics of flow through bottom racks are complex. The present study was directed to estimate the discharge coefficient of a new kind of bottom racks including both transverse and longitudinal bars that named "mesh panel racks" without considering any solids in the fluid. This kind of bottom intake has advantages from structural point of view and has less deformation under static and dynamic loads. Laboratory setup with three mesh panel intakes was built and the effects of various parameters such as racks slope, porosity and geometry were explored. A dimensional analysis using Buckingham theory showed the effective hydraulic and geometric factors that affect the discharge coefficient (Cd of bottom racks. Then, a statistical approach to determine the discharge coefficient of a rack structure was developed with linear and nonlinear regression using SPSS software. The efficiency of the proposed technique is high enough that the associated error is limited to 10%. Finally, hydraulic performance of mesh panel intakes was compared with regular type of bottom intakes, which consist of longitudinal bars. For this purpose, diverted discharge through both type of intakes calculated in same situation

Reliability Study in Solar Panels

OpenAIRE

Español Lifante, Albert

2012-01-01

Crystalline silicon Modules are formed by single silicon photovoltaic cells. Since each one of these cells individually contributes to the overall electric power of the panel, the failure of one of them directly affects to its benefits and performance. To Minimize these negative effects, junction boxes with few bypass diodes are usually included in Photovoltaic Solar panels. A still experimental way to built solar panels is to integrate bypass diodes in every single cell, which would in...

Are Final Comments in Web Survey Panels Associated with Next-Wave Attrition?

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Cynthia McLauchlan

2016-12-01

Full Text Available Near the end of a web survey respondents are often asked whether they have further comments. Such final comments are usually ignored, in part because open-ended questions are challenging to analyse. We explored whether final comments are associated with next-wave attrition in survey panels. We categorized a random sample of final comments in the Longitudinal Studies for the Social Sciences (LISS panel and Dutch Immigrant panel into one of eight categories (neutral, positive, six subcategories of negative and regressed the indicator of next-wave attrition on comment length, comment category and socio-demographic variables. In the Immigrant panel we found shorter final comments (55 words with decreased next-wave attrition relative to making no comment. Comments about unclear survey questions quadruple the odds of attrition and “other” (uncategorized negative comments almost double the odds of attrition. In the LISS panel, making a comment (vs. not and comment length are not associated with attrition. However, when specifying individual comment categories, neutral comments are associated with half the odds of attrition relative to not making a comment.

Static and fatigue experimental tests on a full scale fuselage panel and FEM analyses

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Raffaele Sepe

2016-02-01

Full Text Available A fatigue test on a full scale panel with complex loading condition and geometry configuration has been carried out using a triaxial test machine. The demonstrator is made up of two skins which are linked by a transversal butt-joint, parallel to the stringer direction. A fatigue load was applied in the direction normal to the longitudinal joint, while a constant load was applied in the longitudinal joint direction. The test panel was instrumented with strain gages and previously quasi-static tests were conducted to ensure a proper load transferring to the panel. In order to support the tests, geometric nonlinear shell finite element analyses were conducted to predict strain and stress distributions. The demonstrator broke up after about 177000 cycles. Subsequently, a finite element analysis (FEA was carried out in order to correlate failure events; due to the biaxial nature of the fatigue loads, Sines criterion was used. The analysis was performed taking into account the different materials by which the panel is composed. The numerical results show a good correlation with experimental data, successfully predicting failure locations on the panel.

Panel Analysis

DEFF Research Database (Denmark)

Brænder, Morten; Andersen, Lotte Bøgh

2014-01-01

Based on our 2013-article, ”Does Deployment to War Affect Soldiers' Public Service Motivation – A Panel Study of Soldiers Before and After their Service in Afghanistan”, we present Panel Analysis as a methodological discipline. Panels consist of multiple units of analysis, observed at two or more...... in research settings where it is not possible to distribute units of analysis randomly or where the independent variables cannot be manipulated. The greatest disadvantage in regard to using panel studies is that data may be difficult to obtain. This is most clearly vivid in regard to the use of panel surveys...... points in time. In comparison with traditional cross-sectional studies, the advantage of using panel studies is that the time dimension enables us to study effects. Whereas experimental designs may have a clear advantage in regard to causal inference, the strength of panel studies is difficult to match...

An SEM Approach to Continuous Time Modeling of Panel Data: Relating Authoritarianism and Anomia

Science.gov (United States)

Voelkle, Manuel C.; Oud, Johan H. L.; Davidov, Eldad; Schmidt, Peter

2012-01-01

Panel studies, in which the same subjects are repeatedly observed at multiple time points, are among the most popular longitudinal designs in psychology. Meanwhile, there exists a wide range of different methods to analyze such data, with autoregressive and cross-lagged models being 2 of the most well known representatives. Unfortunately, in these…

Integrated thermal treatment systems study. Internal review panel report

International Nuclear Information System (INIS)

Cudahy, J.; Escarda, T.; Gimpel, R.

1995-04-01

The U.S. Department of Energy (DOE) Office of Technology Development (OTD) commissioned two studies to evaluate nineteen thermal treatment technologies for treatment of DOE mixed low-level waste. These studies were called the Integrated Thermal Treatment System (ITTS) Phase I and Phase II. With the help of the DOE Office of Environmental Management (EM) Mixed Waste Focus Group, OTD formed an ITTS Internal Review Panel to review and comment on the ITTS studies. This Panel was composed of scientists and engineers from throughout the DOE complex, the U.S. Environmental Protection Agency, the California EPA, and private experts. The Panel met from November 15-18, 1994 to review the ITTS studies and to make recommendations on the most promising thermal treatment systems for DOE mixed low-level wastes and on research and development necessary to prove the performance of the technologies. This report describes the findings and presents the recommendations of the Panel

Energy transmission through a double-wall curved stiffened panel using Green's theorem

Science.gov (United States)

Ghosh, Subha; Bhattacharya, Partha

2015-04-01

It is a common practice in aerospace and automobile industries to use double wall panels as fuselage skins or in window panels to improve acoustic insulation. However, the scientific community is yet to develop a reliable prediction method for a suitable vibro-acoustic model for sound transmission through a curved double-wall panel. In this quest, the present work tries to delve into the modeling of energy transmission through a double-wall curved panel. Subsequently the radiation of sound power into the free field from the curved panel in the low to mid frequency range is also studied. In the developed model to simulate a stiffened aircraft fuselage configuration, the outer wall is provided with longitudinal stiffeners. A modal expansion theory based on Green's theorem is implemented to model the energy transmission through an acoustically coupled double-wall curved panel. An elemental radiator approach is implemented to calculate the radiated energy from the curved surface in to the free field. The developed model is first validated with various numerical models available. It has been observed in the present study that the radius of curvature of the surface has a prominent effect on the behavior of radiated sound power into the free field. Effect of the thickness of the air gap between the two curved surfaces on the sound power radiation has also been noted.

Religiousness, spiritual seeking, and personality: findings from a longitudinal study.

Science.gov (United States)

Wink, Paul; Ciciolla, Lucia; Dillon, Michele; Tracy, Allison

2007-10-01

The hypothesis that personality characteristics in adolescence can be used to predict religiousness and spiritual seeking in late adulthood was tested using a structural equation modeling framework to estimate cross-lagged and autoregressive effects in a two-wave panel design. The sample consisted of 209 men and women participants in the Berkeley Guidance and Oakland Growth studies. In late adulthood, religiousness was positively related to Conscientiousness and Agreeableness, and spiritual seeking was related to Openness to Experience. Longitudinal models indicated that Conscientiousness in adolescence significantly predicted religiousness in late adulthood above and beyond adolescent religiousness. Similarly, Openness in adolescence predicted spiritual seeking in late adulthood. The converse effect, adolescent religiousness to personality in late adulthood, was not significant in either model. Among women, adolescent Agreeableness predicted late-life religiousness and adolescent religiousness predicted late-life Agreeableness; both these effects were absent among men. Adolescent personality appears to shape late-life religiousness and spiritual seeking independent of early religious socialization.

A study of the HEB longitudinal dynamics

International Nuclear Information System (INIS)

Larson, D.J.

1993-12-01

A study of the High Energy Booster (HEB) longitudinal dynamics is presented. Full derivations of ramp dependent longitudinal variables are given. The formulas assume that the input magnetic field and beam longitudinal emittance are known as a function of time, and that either the rf voltage or the rf bucket area are known as a function of time. Once these three inputs are specified, the formulas can be used to calculate values for all other longitudinal dynamics variables. The formulas have been incorporated into a single computer code named ELVIRA: Evaluation of Longitudinal Variables in Relativistic Accelerators. The ELVIRA code is documented here in detail. The ELVIRA code is used under two initial longitudinal emittance assumptions to plot ramp functions for the longitudinal dynamics design of the HEB as of May 5, 1992

Study of noise reduction characteristics of double-wall panels

Science.gov (United States)

Navaneethan, R.; Quayle, B.; Stevenson, S.; Graham, M.

1983-05-01

The noise reduction characteristics of general aviation type, flat, double-wall structures were investigated. The experimental study was carried out on 20-by-20 inch panels with an exposed area of 18 by 18 inches. A frequency range from 20 to 5000 Hz was covered. The experimental results, in general, follow the expected trends. At low frequencies the double-wall structures are no better than the single-wall structures. However, for depths normally used in the general aviation industry, the double-wall panels are very attractive. The graphite-spoxy skin panels have higher noise reduction at very low frequencies ( 100 Hz) than the Kevlar skin panels. But the aluminum panels have higher noise reduction in the high frequency region, due to their greater mass. Use of fiberglass insulation is not effective in the low frequency region, and at times it is even negative. But the insulation is effective in the high-frequency region. The theoretical model for predicting the transmission loss of these multilayered panels is also discussed.

Social capital and obesity among adults: Longitudinal findings from the Montreal neighborhood networks and healthy aging panel.

Science.gov (United States)

Wu, Yun-Hsuan; Moore, Spencer; Dube, Laurette

2018-06-01

Curbing the worldwide increase in obesity requires upstream social interventions that modify the environment in which obesity emerges. Recent studies have suggested that social capital and networks may influence a person's risk of obesity. Yet, few longitudinal studies have assessed whether social capital and networks reduce obesity risk in adult populations. In this study, the data come from three waves (2008, 2010, and 2013) of the Montreal Neighborhood Networks and Health Aging Panel (N=2606). Self-reported height and weight were used to calculate body mass index (BMI) with obesity defined as a BMI>30. Name and position generator instruments captured network measures of social capital, including: (1) upper reachability, (2) range, (3) diversity and (4) the number of kin ties. Questions on generalized trust and participation were used to assess cognitive and structural dimensions of social capital. Separate random effects logistic regression was used to examine the association among social network characteristics, social capital, and obesity. We found the greater the number of kin ties in a person's network, the greater the risk of obesity (OR: 1.33, 95% CI: 1.08-1.62). Adults with higher network diversity (OR: 0.83, 95% CI: 0.72-0.96) and high generalized trust (OR: 0.52, 95% CI: 0.35-0.77) were at a lower the risk of obesity. The current study confirmed that higher network capital and trust were protective against obesity, while having kin ties was not. Disentangling the multidimensional role that social capital plays can lead to more effective interventions to reduce obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

Locus of control and frequency of physician visits: Results of a population-based longitudinal study in Germany.

Science.gov (United States)

Hajek, André; König, Hans-Helmut

2017-09-01

To examine the role of internal and external locus of control (LOC) in the frequency of physician visits longitudinally. A nationally representative, longitudinal cohort study of German households. Data were used from the years 2005 and 2010. Data were gathered from the German Socio-Economic Panel (GSOEP). The ten internal and external LOC items in the SOEP are based on a scale by Krampen. The number of physician visits in the last 3 months was used as outcome variable. According to Andersen's behavioural model, predisposing characteristics, enabling resources, and need factors were included as control variables. Fixed-effects Poisson regressions showed that physician visits increased with increasing external LOC, whereas changes in internal LOC were not associated with changes in physician visits. Furthermore, physician visits increased with need factors (decreased self-rated health; onset of disability), whereas predisposing characteristics and the enabling resources were not associated with physician visits. Our findings emphasize the meaning of changes in external LOC for physician visits. As there is evidence that interventions can change the LOC, efforts to modify external LOC might be beneficial for the health care system. Statement of contribution What is already known on this subject? A few cross-sectional studies have investigated the association between locus of control (LOC) and health care use. Longitudinal studies are needed to get a deeper understanding of the causal relationship between these factors. What does this study add? Our longitudinal study provides insights into the impact of general internal and external LOC on physician visits. This is the first study examining the long-term relation in Germany using a population-based sample. © 2017 The British Psychological Society.

Case Study - Monitoring the Photovoltaic Panels

OpenAIRE

PACURAR Ana Talida; TOADER Dumitru; PACURAR Cristian

2014-01-01

The photovoltaic cell represents one of the most dynamic and attractive way to converts renewable energy sources in electricity production. That means to convert solar energy into electricity. In this paper is presented a analogy between two types of photovoltaic panels installed, with educational role for students. Also the objective of this paper is to estimate the performance of photovoltaic panels and to provide the best solution for industry. These two types of photovoltaic panels wer...

Stress-wave velocity of wood-based panels: effect of moisture, product type, and material direction

Science.gov (United States)

Guangping Han; Qinglin Wu; Xiping Wang

2006-01-01

The effect of moisture on longitudinal stress-wave velocity (SWV), bending stiffness. and bending strength of commercial oriented strandboard, plywood. particleboard. and southern pine lumber was evaluated. It was shown that the stress-wave verocity decreased in general with increases in panel moisture content (MC). At a given MC level. SWV varied with panel type and...

Generalized latent variable modeling multilevel, longitudinal, and structural equation models

CERN Document Server

Skrondal, Anders; Rabe-Hesketh, Sophia

2004-01-01

This book unifies and extends latent variable models, including multilevel or generalized linear mixed models, longitudinal or panel models, item response or factor models, latent class or finite mixture models, and structural equation models.

Retrenchments in unemployment insurance benefits and wage inequality: Longitudinal evidence from the Netherlands, 1985–2000

NARCIS (Netherlands)

Mooi-Reci, I.

2012-01-01

This study includes retrenchments in unemployment insurance (UI) benefits as an understudied mechanism to investigate possible explanations for wage inequality in the labor market. Using longitudinal data from the Dutch Labor Supply Panel (OSA) over the period 1985-2000, and adopting a

Associations between Obesity and Spinal Diseases: A Medical Expenditure Panel Study Analysis

Directory of Open Access Journals (Sweden)

Binwu Sheng

2017-02-01

Full Text Available Background: The link between body weight status and spinal diseases has been suggested by a number of cross-sectional and cohort studies with a limited range of patient populations. No population-representative samples have been used to examine the link between obesity and spinal diseases. The present study is based on a nationally representative sample drawn from the Medical Expenditure Panel Survey. Methods: Using the cross-sectional sample of the 2014 Medical Expenditure Panel Study, we built four weighted logistic regression analyses of the associations between body weight status and the following four spinal diseases: low back pain, spondylosis, other cervical disorders and intervertebral disc disorder (IDD. Each respondent’s body weight status was used as the key independent variable with three categories: normal/underweight, overweight, and obese. We controlled for marital status, gender, age, smoking status, household income, health insurance coverage, educational attainment and the use of health services for other major categories of diseases. Results: A total sample of 23,048 respondents was used in our analysis. Overweight and obese respondents, as compared to normal/underweight respondents, were more likely to develop lower back problems (Overweight: logged odds = 0.218, p < 0.01; Obese: logged odds = 0.395, p < 0.001 and IDD (Overweight: logged odds = 0.441, p < 0.05; Obese: logged odds = 0.528, p < 0.001. The associations between bodyweight status and spondylitis were statistically insignificant (Overweight: logged odds = 0.281, p = 0.442; Obese: logged odds = 0.680, p = 0.104. The associations between body weight status and other cervical disorders (Overweight: logged odds = −0.116, p = 0.304; Obese: logged odds = −0.160, p = 0.865 were statistically insignificant. Conclusions: As the first study using a national sample to study bodyweight and spinal diseases, our paper supports the hypothesis that obesity adds to the burden

Social desirability and self-reported health risk behaviors in web-based research: three longitudinal studies

Directory of Open Access Journals (Sweden)

Göritz Anja S

2010-11-01

Full Text Available Abstract Background These studies sought to investigate the relation between social desirability and self-reported health risk behaviors (e.g., alcohol use, drug use, smoking in web-based research. Methods Three longitudinal studies (Study 1: N = 5612, 51% women; Study 2: N = 619, 60%; Study 3: N = 846, 59% among randomly selected members of two online panels (Dutch; German using several social desirability measures (Marlowe-Crowne Scale; Balanced Inventory of Desirable Responding; The Social Desirability Scale-17 were conducted. Results Social desirability was not associated with self-reported current behavior or behavior frequency. Socio-demographics (age; sex; education did not moderate the effect of social desirability on self-reported measures regarding health risk behaviors. Conclusions The studies at hand provided no convincing evidence to throw doubt on the usefulness of the Internet as a medium to collect self-reports on health risk behaviors.

Unemployment scarring by gender: Human capital depreciation or stigmatization? Longitudinal evidence from the Netherlands, 1980-2000

NARCIS (Netherlands)

Mooi-Reci, Irma; Ganzeboom, H.B.G.

2015-01-01

Using longitudinal data from the Dutch Labor Force Supply Panel (OSA), this article examines how unemployment scarring (i.e., wage setbacks following unemployment) and its underlying mechanisms operate across gender in the Netherlands over the period 1985-2000. A series of fixed effect panel models

Study of the cracking of sandwich panels of plasterboard and rockwool

Directory of Open Access Journals (Sweden)

Alonso, J. A.

2013-09-01

Full Text Available This paper presents the study of plasterboard and rockwool sandwich panels cracking under flexural loading. These panels are usually used to perform interior partition walls and they frequently show cracking pathology due to excessive deflexion of the slabs. There are currently no reliable simulation models and experimental data for the study of this problem. This paper presents the results of an experimental campaign aimed to characterize the fracture behaviour of sandwich panels and their individual components. In addition, the paper presents a cohesive model with embedded crack to simulate the fracture behaviour of the panel. Finally we present the results of tests for mixed mode fracture (tensile / shear commercial panels and their behaviour is reproduced with the cohesive model proposed, yielding a good fit.Este artículo presenta el estudio de la rotura de paneles sándwich de yeso laminado y lana de roca bajo solicitaciones de flexo-tracción dentro de su plano. Estos paneles se emplean para conformar tabiques interiores de edificación y con frecuencia se fisuran por flechas excesivas en los forjados. Actualmente no hay modelos de cálculo fiables ni datos experimentales que permitan estudiar este problema. Este trabajo presenta los resultados de una campaña experimental encaminada a caracterizar el comportamiento en rotura de los paneles sándwich y de sus componentes individuales. Además, se presenta un modelo cohesivo con fisura embebida que permite simular el comportamiento en rotura del panel sándwich conjunto. Por último se presentan los resultados de los ensayos de fractura en modo mixto (tracción/cortante de paneles comerciales y se reproduce su comportamiento con el modelo cohesivo propuesto, obteniéndose un buen ajuste.

A chemometrics study of analytical panels in virgin olive oil. An approach for evaluating panels in training

Directory of Open Access Journals (Sweden)

Aparicio, R.

1991-06-01

Full Text Available A mathematical procedure including Canonical Correlation, Factor and cluster analysis and Multiple Regression was designed to study whether two different sensory panels, with different levels of training, could be considered as a unity. Among others, correlations between each attribute of both panels, matrices of partial correlations, variance explained by the most important factors and similarity among clusters were computed as the procedure to evaluate if a Panel in training works as well as an expertise. In addition, every one of the factors was correlated with the final evaluation of quality for analyzing the interrelationship between the profile notes and the grading table of virgin olive oil quality from a mathematical point of view. Finally, a stepwise multiple correlation analyzes how the panels modeled the evaluated samples. Promising directions for future research are also suggested.

Un procedimiento matemático que incluye Correlación Canónica, Análisis Factorial y de "clusters", y Regresión Múltiple fue diseñado para estudiar si dos paneles analíticos, con diferentes niveles de entrenamiento, podrían ser considerados idénticos. Para evaluar si un panel en o después de un entrenamiento opera tan bien como uno experto, se analizaron las correlaciones entre los atributos de ambos paneles, las matrices de correlaciones parciales, la varianza explicada por los factores más importantes y la similaridad entre los aglomerados ("clusters" entre otras. Además, los tres factores más importantes fueron correlacionados con las valoraciones finales de calidad, para conocer la interrelación entre la hoja de perfil y la tabla de puntuación. Finalmente, un análisis de regresión múltiple permite conocer cómo es el modelo que los paneles han diseñado para muestras de aceite de oliva virgen evaluadas. También se sugieren las tendencias en la investigación futura.

Longitudinal evaluation of the mental health continuum-short form (MHC-SF): Measurement invariance across demographics, physical illness, and mental illness

NARCIS (Netherlands)

Lamers, S.M.A.; Glas, Cornelis A.W.; Westerhof, Gerben Johan; Bohlmeijer, Ernst Thomas

2012-01-01

This study evaluated the measurement invariance of the Mental Health Continuum-Short Form (MHC-SF), a 14-item self-report questionnaire for measuring emotional, social, and psychological well-being. The study draws on data of a representative panel (Longitudinal Internet Studies for the Social

Attrition Bias in Panel Data: A Sheep in Wolf's Clothing? A Case Study Based on the Mabel Survey.

Science.gov (United States)

Cheng, Terence C; Trivedi, Pravin K

2015-09-01

This paper investigates the nature and consequences of sample attrition in a unique longitudinal survey of medical doctors. We describe the patterns of non-response and examine if attrition affects the econometric analysis of medical labour market outcomes using the estimation of physician earnings equations as a case study. We compare the econometric gestimates obtained from a number of different modelling strategies, which are as follows: balanced versus unbalanced samples; an attrition model for panel data based on the classic sample selection model; and a recently developed copula-based selection model. Descriptive evidence shows that doctors who work longer hours, have lower years of experience, are overseas trained and have changed their work location are more likely to drop out. Our analysis suggests that the impact of attrition on inference about the earnings of general practitioners is small. For specialists, there appears to be some evidence for an economically significant bias. Finally, we discuss how the top-up samples in the Medicine in Australia: Balancing Employment and Life survey can be used to address the problem of panel attrition. Copyright © 2015 John Wiley & Sons, Ltd.

Pilot study protocol to inform a future longitudinal study of ageing using linked administrative data: Healthy AGeing in Scotland (HAGIS).

Science.gov (United States)

Douglas, Elaine; Rutherford, Alasdair; Bell, David

2018-01-10

Population ageing is a welcome testament to improvements in the social, economic and health circumstances over the life course. However, these successes necessitate that we understand more about the pathways of ageing to plan and cost our health and social care services, to support our ageing population to live healthier for longer and to make adequate provisions for retirement. Longitudinal studies of ageing facilitate such understanding in many countries around the world. Scotland presently does not have a longitudinal study of ageing, despite dramatic increases to its ageing population and its poor health record. Healthy AGeing in Scotland (HAGIS) constitutes the launch of Scotland's first comprehensive longitudinal study of ageing. A sample of 1000 people aged 50+ years will be invited to take part in a household social survey. The innovative sampling procedure used administrative data to identify eligible households. Anonymised survey responses will be linked to administrative data. Ethics approval was obtained from the host institution for the study design and from the Public Benefits and Privacy Panel for administrative data linkage. Anonymised survey data will be deposited with the UK Data Service. A subset of survey data, harmonised with other global ageing studies, will be available via the Gateway to Global Aging platform. These data will enable powerful cross-country comparisons across the social, economic and health domains that will be relevant for national and international research.Research publications from the HAGIS team will be disseminated through journal articles and national and international conferences. The findings will support current and future research and policy debate on ageing populations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A longitudinal study

OpenAIRE

Kristen, Astrid

2010-01-01

Does playing violent video games increase aggressive behavior over time or is it aggressive children who increasingly seek out (and play) these violent video games? To study such long-term effects a longitudinal design is necessary. Within a field study in a large German city (Kinder, Computer, Hobby, Lernen – KUHL, Freie Universtität Berlin) about 115 elementary school boys attending in the beginning (t1) classrooms of the third and fourth grade and twelve months later (t2) classrooms of the...

Excellent gamer, excellent driver? The impact of adolescents' video game playing on driving behavior: a two-wave panel study.

Science.gov (United States)

Beullens, Kathleen; Roe, Keith; Van den Bulck, Jan

2011-01-01

This study explored the impact of adolescents' playing of racing and drive'em up games on their risky driving behavior. Participants were 354 adolescent boys and girls who took part in a longitudinal panel survey on video game playing and risk taking attitudes, intentions and behaviors. In line with cultivation theory and theory of planned behavior the results showed that (even after controlling for aggression and sensation seeking) video game playing during adolescence succeeded in predicting later risky driving behavior through adolescents' attitudes and intentions to exhibit this behavior in the future. The results suggest that this relationship may in part be explained by the game content. Copyright © 2010 Elsevier Ltd. All rights reserved.

Experimental study of efficiency of solar panel by phase change material cooling

Science.gov (United States)

Wei, Nicholas Tan Jian; Nan, Wong Jian; Guiping, Cheng

2017-07-01

The dependence of efficiency of photovoltaic panels on their temperature during operation is a major concern for developers and users. In this paper, a phase change material (PCM) cooling system was designed for a 60W mono-crystalline solar panel. Tealights candle was selected as the cooling medium. The solar irradiance was recorded using Kipp & Zonen CMP3 pyranometer and Meteon data logger. Temperature distribution on the surface of solar panel, output voltage and output current of solar panel were measured. The average irradiance throughout data collection was found to be 705W/m2 and highest irradiance was 1100 W/m2. The average solar panel temperature was 43.6°C and a maximum temperature of 53°C was at the center of solar panel. Results showed that average power output and efficiency of the solar panel were 44.4W and 15%, respectively. It was found that the higher the solar irradiance, the lower the efficiency of solar panel and the higher the temperature and power output of solar panel. This is due to the fact that high irradiance results in high power input and high solar panel temperature. But high PV panel temperature reduces its power output. Therefore, the increase of power input outweighs that of power output, which leads to the decrease of efficiency of solar panel with the increase of solar irradiance. Compared with solar panel without cooling, the power output and efficiency of solar panel did not increase with PCM cooling. It indicates that Tealights candle as PCM cooling is not efficient in improving the efficiency of solar panel in this study.

What Comes First, Job Burnout or Secondary Traumatic Stress? Findings from Two Longitudinal Studies from the U.S. and Poland.

Science.gov (United States)

Shoji, Kotaro; Lesnierowska, Magdalena; Smoktunowicz, Ewelina; Bock, Judith; Luszczynska, Aleksandra; Benight, Charles C; Cieslak, Roman

2015-01-01

This longitudinal research examined the directions of the relationships between job burnout and secondary traumatic stress (STS) among human services workers. In particular, using cross-lagged panel design, we investigated whether job burnout predicts STS at 6-month follow up or whether the level of STS symptoms explains job burnout at 6-month follow-up. Participants in Study 1 were behavioral or mental healthcare providers (N = 135) working with U.S. military personnel suffering from trauma. Participants in Study 2 were healthcare providers, social workers, and other human services professions (N = 194) providing various types of services for civilian trauma survivors in Poland. The cross-lagged analyses showed consistent results for both longitudinal studies; job burnout measured at Time 1 led to STS at Time 2, but STS assessed at Time 1 did not lead to job burnout at Time 2. These results contribute to a discussion on the origins of STS and job burnout among human services personnel working in highly demanding context of work-related secondary exposure to traumatic events and confirm that job burnout contributes to the development of STS.

Ballistic study of Tensylon®–based panels

Directory of Open Access Journals (Sweden)

L-C. Alil

2018-06-01

Full Text Available Ballistic protection is a matter of interest requested by civilian as well as military needs. The last decade has witnessed an increase in the use of light weight and efficient armour systems. These panels may be used for body protection as well as light vehicle protection against small calibres or to enhance the protection level of heavier vehicles with decreasing or maintaining their weight penalty. Ultra high molecular weight polyethylene is a material of interest for light weight armour applications. The authors designed panels made of hot–pressed Tensylon® in different configurations with thin steel sheets as a backing and shield protection. Comparison of their ballistic performance to the theory predictions reveals the improved ballistic response of the panels. In addition, a non–pressed Tensylon® panel has been tested in order to facilitate the observations of the failure mechanisms inside the panels. Even if not suitable for practical use, such non–pressed panels clearly reveal the dynamic processes at micro–scale that occur during the impact. The failure mechanisms of the material under bullet penetration are discussed based on photography, optical microscopy and scanning electron microscopy. The supposed effects of the panel pressing are discussed based on the observed difference between pressed and non–pressed structures ballistic response.

The Latent Curve ARMA (P, Q) Panel Model: Longitudinal Data Analysis in Educational Research and Evaluation

Science.gov (United States)

Sivo, Stephen; Fan, Xitao

2008-01-01

Autocorrelated residuals in longitudinal data are widely reported as common to longitudinal data. Yet few, if any, researchers modeling growth processes evaluate a priori whether their data have this feature. Sivo, Fan, and Witta (2005) found that not modeling autocorrelated residuals present in longitudinal data severely biases latent curve…

Delamination tolerance studies in laminated composite panels

Indian Academy of Sciences (India)

Abstract. Determination of levels of tolerance in delaminated composite panels is an important issue in composite structures technology. The primary intention is to analyse delaminated composite panels and estimate Strain. Energy Release Rate (SERR) parameters at the delamination front to feed into acceptability criteria.

Pain and Joy of a Panel Survey on Transport Studies

Energy Technology Data Exchange (ETDEWEB)

Comendador Arquero, María Eugenia López-Lambas

2016-07-01

Over ten years ago, it was established that the most frequent reason that motivates a panel survey on transport studies is the evaluation of a change in the transportation system, or a specific transportation-planning project, especially when the project involves novel elements. From a statistical viewpoint, a panel survey has the definite advantage to offer more accurate estimatesof changes than cross-sectional surveys for the same sample size. Observing travel patterns of individuals and households overseveral consecutive days, has offered insights into activity scheduling and travel planning. Variability in travel patterns has important policy implications as well, but how much effort is worth to design a panel survey? To evaluate the effects of the transport policies introduced in Madrid during the last five years, a ‘short-long’ panel survey wasbuilt, based on a sample of a Madrid-worker subpopulation most affected by those recent changes in transport policy. The paper describes both the design and construction of the panel based on GPS technology, and presents some results based on an analysis of its two waves; for example, it registered an increment of public transport use and walking trips in 10%. The panel overcomes the known attrition problem thanks to providing incentives, maintaining contact, using the same interviewer for the same respondents, and conducting face-to-face interviews. (Author)

A Longitudinal Investigation of the Preservice Science Teachers' Beliefs about Science Teaching during a Science Teacher Training Programme

Science.gov (United States)

Buldur, Serkan

2017-01-01

The aim of this longitudinal study was to investigate the changes in preservice science teachers' beliefs about science teaching during a science teacher training programme. The study was designed as a panel study, and the data were collected from the same participants at the end of each academic year during a four-year period. The participants…

Live load distribution on longitudinal glued-laminated timber deck bridges : final report : conclusions and recommendations

Science.gov (United States)

Fouad Fanous; Jeremy May; Terry Wipf; Michael Ritter

2010-01-01

Over the past few years the United States Department of Agriculture (USDA), Forest Products Laboratory (FPL), and the Federal Highway Administration (FHWA) have supported several research programs. This paper is a result of a study sponsored by FPL, with the objective of determining how truckloads are distributed to the deck panels of a longitudinal glued-laminated...

Study of CSR longitudinal bunch compression cavity

International Nuclear Information System (INIS)

Yin Dayu; Li Peng; Liu Yong; Xie Qingchun

2009-01-01

The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring (CSR)is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch,which can be produced by non-adiabatic compression of bunch implemented by a fast compression with 90 degree rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RF-voltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMET-FT-1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238 U 72+ with 250 MeV/u will be compressed from 200 ns to 50 ns.The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80 kV, and the cavity can be used to compress heavy ions in the CSR. (authors)

[Using consumer panels in public health observational studies].

Science.gov (United States)

Matilla-Santander, Nuria; Fu, Marcela; Ballbè, Montse; Lidón-Moyano, Cristina; Martín-Sánchez, Juan Carlos; Fernández, Esteve; Martínez-Sánchez, José M

Consumer panels are a market research method useful for gathering information about low-frequency or difficult-access customers. The objective of this field-note is to explain our experience using this method in a cross-sectional public health study on the use of electronic cigarettes. After taking into account other non-probabilistic sampling techniques to obtain a huge sample of electronic-cigarette users (n=600), in the end we decided to use consumer panels (recruiters) because of the relative short duration of the field work and the high representativeness of the sample. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Quality of Life in and After Spinal Cord Injury Rehabilitation: A Longitudinal Multicenter Study

Science.gov (United States)

Kennedy, P.; Elfström, M.L.; Ballert, C.S.

2014-01-01

Purpose: To investigate the changes in quality of life (QOL) in persons with spinal cord injury (SCI) and their close persons during the first 2 years post injury. Method: Longitudinal multiple sample multiple wave panel design. Data included 292 patients recruited from Austrian British German Irish and Swiss specialist SCI rehabilitation centers and 55 of their close persons. Questionnaire booklets were administered at 6 weeks 12 weeks 1 year and 2 years after injury to both samples. Results: Study 1 investigated the WHOQOL-BREF domains in individuals with SCI and found differences mostly in the physical domain indicating that QOL increases for persons with SCI from onset. An effect of the culture was observed in the psychological and environmental domains with higher QOL scores in the German-speaking sample. Study 2 compared individuals with SCI to their close persons and found differences in the physical environmental and social domains over time. The scores on the psychological dimension did not significantly differ between the persons with SCI and their close persons over time. Conclusion: QOL measured by the WHOQOL-BREF shows that QOL changes during rehabilitation and after discharge. Apart from the physical dimension the persons with SCI and their close persons seem to experience a similar change in QOL. Further longitudinal research is suggested to clarify the mutual adjustment process of people with SCI and their close persons and to explore cultural differences in QOL between English-and German-speaking countries. PMID:25484566

BUCLASP 3: A computer program for stresses and buckling of heated composite stiffened panels and other structures, user's manual

Science.gov (United States)

Tripp, L. L.; Tamekuni, M.; Viswanathan, A. V.

1973-01-01

The use of the computer program BUCLASP3 is described. The code is intended for thermal stress and instability analyses of structures such as unidirectionally stiffened panels. There are two types of instability analyses that can be effected by PAINT; (1) thermal buckling, and (2) buckling due to a specified inplane biaxial loading. Any structure that has a constant cross section in one direction, that may be idealized as an assemblage of beam elements and laminated flat and curved plate strip-elements can be analyzed. The two parallel ends of the panel must be simply supported, whereas arbitrary elastic boundary conditions may be imposed along any one or both external longitudinal side. Any variation in the temperature rise (from ambient) through the cross section of a panel is considered in the analyses but it must be assumed that in the longitudinal direction the temperature field is constant. Load distributions for the externally applied inplane biaxial loads are similar in nature to the permissible temperature field.

Estimating increment-decrement life tables with multiple covariates from panel data: the case of active life expectancy.

Science.gov (United States)

Land, K C; Guralnik, J M; Blazer, D G

1994-05-01

A fundamental limitation of current multistate life table methodology-evident in recent estimates of active life expectancy for the elderly-is the inability to estimate tables from data on small longitudinal panels in the presence of multiple covariates (such as sex, race, and socioeconomic status). This paper presents an approach to such an estimation based on an isomorphism between the structure of the stochastic model underlying a conventional specification of the increment-decrement life table and that of Markov panel regression models for simple state spaces. We argue that Markov panel regression procedures can be used to provide smoothed or graduated group-specific estimates of transition probabilities that are more stable across short age intervals than those computed directly from sample data. We then join these estimates with increment-decrement life table methods to compute group-specific total, active, and dependent life expectancy estimates. To illustrate the methods, we describe an empirical application to the estimation of such life expectancies specific to sex, race, and education (years of school completed) for a longitudinal panel of elderly persons. We find that education extends both total life expectancy and active life expectancy. Education thus may serve as a powerful social protective mechanism delaying the onset of health problems at older ages.

What Comes First, Job Burnout or Secondary Traumatic Stress? Findings from Two Longitudinal Studies from the U.S. and Poland.

Directory of Open Access Journals (Sweden)

Kotaro Shoji

Full Text Available This longitudinal research examined the directions of the relationships between job burnout and secondary traumatic stress (STS among human services workers. In particular, using cross-lagged panel design, we investigated whether job burnout predicts STS at 6-month follow up or whether the level of STS symptoms explains job burnout at 6-month follow-up. Participants in Study 1 were behavioral or mental healthcare providers (N = 135 working with U.S. military personnel suffering from trauma. Participants in Study 2 were healthcare providers, social workers, and other human services professions (N = 194 providing various types of services for civilian trauma survivors in Poland. The cross-lagged analyses showed consistent results for both longitudinal studies; job burnout measured at Time 1 led to STS at Time 2, but STS assessed at Time 1 did not lead to job burnout at Time 2. These results contribute to a discussion on the origins of STS and job burnout among human services personnel working in highly demanding context of work-related secondary exposure to traumatic events and confirm that job burnout contributes to the development of STS.

What Comes First, Job Burnout or Secondary Traumatic Stress? Findings from Two Longitudinal Studies from the U.S. and Poland

Science.gov (United States)

Shoji, Kotaro; Lesnierowska, Magdalena; Smoktunowicz, Ewelina; Bock, Judith; Luszczynska, Aleksandra; Benight, Charles C.; Cieslak, Roman

2015-01-01

This longitudinal research examined the directions of the relationships between job burnout and secondary traumatic stress (STS) among human services workers. In particular, using cross-lagged panel design, we investigated whether job burnout predicts STS at 6-month follow up or whether the level of STS symptoms explains job burnout at 6-month follow-up. Participants in Study 1 were behavioral or mental healthcare providers (N = 135) working with U.S. military personnel suffering from trauma. Participants in Study 2 were healthcare providers, social workers, and other human services professions (N = 194) providing various types of services for civilian trauma survivors in Poland. The cross-lagged analyses showed consistent results for both longitudinal studies; job burnout measured at Time 1 led to STS at Time 2, but STS assessed at Time 1 did not lead to job burnout at Time 2. These results contribute to a discussion on the origins of STS and job burnout among human services personnel working in highly demanding context of work-related secondary exposure to traumatic events and confirm that job burnout contributes to the development of STS. PMID:26305222

Performance study on the east-west oriented single-axis tracked panel

International Nuclear Information System (INIS)

Chang, Tian Pau

2009-01-01

A theoretical study on the performance of an east-west oriented single-axis tracked panel was originally proposed in this paper. Mathematic expressions applicable for calculating the angle that the tracked panel should rotate by to follow the Sun are derived. The incident angle of sunlight upon the panel as well as the instantaneous increments of solar energy captured by the panel relative to a fixed horizontal surface are then demonstrated graphically. To simulate different operation environments, three kinds of radiation sources will be considered, i.e. the extraterrestrial radiation, global radiation predicted by empirical models under clear sky situation and global radiation observed in Taiwan. Simulation results show that the yearly gains correlate positively with the radiation level, i.e. 21.2%, 13.5% and 7.4% for the extraterrestrial, predicted and observed radiations, respectively, which are far less than those obtained from a north-south oriented single-axis tracked panel. The irradiation increases with the maximum rotation angle of the panel, the benefit of increasing the rotation in overcast environment is not as good as in clear sky, for annual energy collection 45 o is recommended. The irradiation received decreases with latitude, but it has a greater gain in higher latitude zone.

A panel study of nuclear energy consumption and economic growth

International Nuclear Information System (INIS)

Apergis, Nicholas; Payne, James E.

2010-01-01

This study examines the relationship between nuclear energy consumption and economic growth for sixteen countries within a multivariate panel framework over the period 1980-2005. Pedroni's (1999, 2004) heterogeneous panel cointegration test reveals there is a long-run equilibrium relationship between real GDP, nuclear energy consumption, real gross fixed capital formation, and the labor force with the respective coefficients positive and statistically significant. The results of the panel vector error correction model finds bidirectional causality between nuclear energy consumption and economic growth in the short-run while unidirectional causality from nuclear energy consumption to economic growth in the long-run. Thus, the results provide support for the feedback hypothesis associated with the relationship between nuclear energy consumption and economic growth.

A Longitudinal Study of Adolescent Adjustment Following Family Transitions

Science.gov (United States)

Ruschena, Eda; Prior, Margot; Sanson, Ann; Smart, Diana

2005-01-01

Background: This study examined the impact of family transitions, that is, parental separation, divorce, remarriage and death, upon the lives of Australian children and adolescents in a longitudinal study of temperament and development. Methods: Using longitudinal and concurrent questionnaire data, outcomes for young people experiencing…

The nature and causes of attrition in the British Household Panel Study

OpenAIRE

Uhrig, S.C. Noah

2008-01-01

Panel attrition is a process producing data absent from panel records due to survey non-participation or other data unavailability. I examine the nature and causes of attrition resulting from non-contact and survey refusal in the British Household Panel Study. Focusing on non-response transitions amongst Wave 1 respondents using discrete time transition models, I locate attrition at first non-response over the first 14 waves. Physical impediments to contact, less time spent at home and high l...

Whole field strain measurement in critical thin adhesive layer of single- and double-sided repaired CFRP panel using DIC

Science.gov (United States)

Kashfuddoja, Mohammad; Ramji, M.

2015-03-01

In the present work, the behavior of thin adhesively layer in patch repaired carbon fiber reinforced polymer (CFRP) panel under tensile load is investigated experimentally using digital image correlation (DIC) technique. The panel is made of Carbon/epoxy composite laminate and the stacking sequence in the panel is [0º]4. A circular hole of 10 mm diameter (d) is drilled at the center of the panel to mimic the case of low velocity impact damage removal. The panel with open hole is repaired with double sided (symmetrical) and single sided (unsymmetrical) rectangular patch made of same panel material having stacking sequence of [0º]3. Araldite 2011 is used for bonding the patch onto the panel over the damaged area. The global behavior of thin adhesive layer is examined by analyzing whole field strain distribution using DIC. Longitudinal, peel and shear strain field in both double and single sided repair configuration is studied and a compression is made between them. An estimate of shear transfer length which is an essential parameter in arriving at an appropriate overlap length in patch design is proposed from DIC and FEA. Damage development, failure mechanism and load displacement behavior is also investigated. The experimental results are compared with the numerical predictions.

Clinical management and burden of bipolar disorder: a multinational longitudinal study (WAVE-bd Study

Directory of Open Access Journals (Sweden)

Moreno-Manzanaro Miriam

2011-04-01

Full Text Available Abstract Background Studies in bipolar disorder (BD to date are limited in their ability to provide a whole-disease perspective - their scope has generally been confined to a single disease phase and/or a specific treatment. Moreover, most clinical trials have focused on the manic phase of disease, and not on depression, which is associated with the greatest disease burden. There are few longitudinal studies covering both types of patients with BD (I and II and the whole course of the disease, regardless of patients' symptomatology. Therefore, the Wide AmbispectiVE study of the clinical management and burden of Bipolar Disorder (WAVE-bd (NCT01062607 aims to provide reliable information on the management of patients with BD in daily clinical practice. It also seeks to determine factors influencing clinical outcomes and resource use in relation to the management of BD. Methods WAVE-bd is a multinational, multicentre, non-interventional, longitudinal study. Approximately 3000 patients diagnosed with BD type I or II with at least one mood event in the preceding 12 months were recruited at centres in Austria, Belgium, Brazil, France, Germany, Portugal, Romania, Turkey, Ukraine and Venezuela. Site selection methodology aimed to provide a balanced cross-section of patients cared for by different types of providers of medical aid (e.g. academic hospitals, private practices in each country. Target recruitment percentages were derived either from scientific publications or from expert panels in each participating country. The minimum follow-up period will be 12 months, with a maximum of 27 months, taking into account the retrospective and the prospective parts of the study. Data on demographics, diagnosis, medical history, clinical management, clinical and functional outcomes (CGI-BP and FAST scales, adherence to treatment (DAI-10 scale and Medication Possession Ratio, quality of life (EQ-5D scale, healthcare resources, and caregiver burden (BAS scale

Panel 5: Microbiology and Immunology Panel

Science.gov (United States)

Murphy, Timothy F.; Chonmaitree, Tasnee; Barenkamp, Stephen; Kyd, Jennelle; Nokso-Koivisto, Johanna; Patel, Janak A.; Heikkinen, Terho; Yamanaka, Noboru; Ogra, Pearay; Swords, W. Edward; Sih, Tania; Pettigrew, Melinda M.

2014-01-01

Objective The objective is to perform a comprehensive review of the literature from January 2007 through June 2011 on the virology, bacteriology, and immunology related to otitis media. Data Sources PubMed database of the National Library of Medicine. Review Methods Three subpanels with co-chairs comprising experts in the virology, bacteriology, and immunology of otitis media were formed. Each of the panels reviewed the literature in their respective fields and wrote draft reviews. The reviews were shared with all panel members, and a second draft was created. The entire panel met at the 10th International Symposium on Recent Advances in Otitis Media in June 2011 and discussed the review and refined the content further. A final draft was created, circulated, and approved by the panel. Conclusion Excellent progress has been made in the past 4 years in advancing an understanding of the microbiology and immunology of otitis media. Advances include laboratory-based basic studies, cell-based assays, work in animal models, and clinical studies. Implications for Practice The advances of the past 4 years formed the basis of a series of short-term and long-term research goals in an effort to guide the field. Accomplishing these goals will provide opportunities for the development of novel interventions, including new ways to better treat and prevent otitis media. PMID:23536533

The Mutual Relationship Between Men's Drinking and Depression: A 4-Year Longitudinal Analysis.

Science.gov (United States)

Lee, Soo Bi; Chung, Sulki; Lee, HaeKook; Seo, Jeong Seok

2018-03-17

The purpose of the current study was to examine the longitudinal reciprocal relationship between depression and drinking among male adults from the general population. This study used a panel dataset from the Korean Welfare Panel (from 2011 to 2014). The subjects were 2511 male adults aged between 20 and 65 years. Based on the Korean Version of the Alcohol Use Disorders Identification Test (AUDIT-K) scores, 2191 subjects were categorized as the control group (AUDIT-K AUDIT-K ≥ 12). An autoregressive cross-lagged modelling analysis was performed to investigate the mutual relationship between problem drinking and depression measured consecutively over time. The results indicated that alcohol drinking and depression were stable over time. In the control group, there was no significant causal relationship between problem drinking and depression while in the problem drinking group, drinking in the previous year significantly influenced depression in the following second, third and fourth years. This study compared normal versus problem drinkers and showed a 4-year mutual causal relationship between depression and drinking. No longitudinal interaction between drinking and depression occurred in normal drinkers, while drinking intensified depression over time in problem drinkers. This study found that problem drinking was a risk factor for development of depression. Therefore, more attention should be given to problem alcohol use in the general population and evaluation of past alcohol use history in patients with depressive disorders.

Statistical Power in Longitudinal Network Studies

NARCIS (Netherlands)

Stadtfeld, Christoph; Snijders, Tom A. B.; Steglich, Christian; van Duijn, Marijtje

2018-01-01

Longitudinal social network studies may easily suffer from a lack of statistical power. This is the case in particular for studies that simultaneously investigate change of network ties and change of nodal attributes. Such selection and influence studies have become increasingly popular due to the

Benevolent Sexism, Attitudes Toward Motherhood, and Reproductive Rights: A Multi-Study Longitudinal Examination of Abortion Attitudes.

Science.gov (United States)

Huang, Yanshu; Davies, Paul G; Sibley, Chris G; Osborne, Danny

2016-07-01

Although Benevolent Sexism (BS)-an ideology that highly reveres women who conform to traditional gender roles-is cloaked in a superficially positive tone, being placed upon a pedestal is inherently restrictive. Accordingly, because the paternalistic beliefs associated with BS are based on the idealization of traditional gender roles (which include motherhood), BS should predict people's attitudes toward women's reproductive rights. Using data from a nationwide longitudinal panel study (N = 12,299), Study 1 showed that BS (but not Hostile Sexism) had cross-lagged effects on opposition to both elective and traumatic abortion. Study 2 (N = 309) extended these findings by showing that the relationship between BS and support for abortion was fully mediated by attitudes toward motherhood. These results highlight the pernicious nature of BS by demonstrating that the idealization of women-and motherhood, in particular-comes at a substantial cost (namely, the restriction of women's reproductive rights). © 2016 by the Society for Personality and Social Psychology, Inc.

Sound absorption study on acoustic panel from kapok fiber and egg tray

Science.gov (United States)

Kaamin, Masiri; Mahir, Nurul Syazwani Mohd; Kadir, Aslila Abd; Hamid, Nor Baizura; Mokhtar, Mardiha; Ngadiman, Norhayati

2017-12-01

Noise also known as a sound, especially one that is loud or unpleasant or that causes disruption. The level of noise can be reduced by using sound absorption panel. Currently, the market produces sound absorption panel, which use synthetic fibers that can cause harmful effects to the health of consumers. An awareness of using natural fibers from natural materials gets attention of some parties to use it as a sound absorbing material. Therefore, this study was conducted to investigate the potential of sound absorption panel using egg trays and kapok fibers. The test involved in this study was impedance tube test which aims to get sound absorption coefficient (SAC). The results showed that there was good sound absorption at low frequency from 0 Hz up to 900 Hz where the maximum absorption coefficient was 0.950 while the maximum absorption at high frequencies was 0.799. Through the noise reduction coefficient (NRC), the material produced NRC of 0.57 indicates that the materials are very absorbing. In addition, the reverberation room test was carried out to get the value of reverberation time (RT) in unit seconds. Overall this panel showed good results at low frequencies between 0 Hz up to 1500 Hz. In that range of frequency, the maximum reverberation time for the panel was 3.784 seconds compared to the maximum reverberation time for an empty room was 5.798 seconds. This study indicated that kapok fiber and egg tray as the material of absorption panel has a potential as environmental and cheap products in absorbing sound at low frequency.

Pathological video game use among youths: a two-year longitudinal study.

Science.gov (United States)

Gentile, Douglas A; Choo, Hyekyung; Liau, Albert; Sim, Timothy; Li, Dongdong; Fung, Daniel; Khoo, Angeline

2011-02-01

We aimed to measure the prevalence and length of the problem of pathological video gaming or Internet use, to identify risk and protective factors, to determine whether pathological gaming is a primary or secondary problem, and to identify outcomes for individuals who become or stop being pathological gamers. A 2-year, longitudinal, panel study was performed with a general elementary and secondary school population in Singapore, including 3034 children in grades 3 (N = 743), 4 (N = 711), 7 (N = 916), and 8 (N = 664). Several hypothesized risk and protective factors for developing or overcoming pathological gaming were measured, including weekly amount of game play, impulsivity, social competence, depression, social phobia, anxiety, and school performance. The prevalence of pathological gaming was similar to that in other countries (∼9%). Greater amounts of gaming, lower social competence, and greater impulsivity seemed to act as risk factors for becoming pathological gamers, whereas depression, anxiety, social phobias, and lower school performance seemed to act as outcomes of pathological gaming. This study adds important information to the discussion about whether video game "addiction" is similar to other addictive behaviors, demonstrating that it can last for years and is not solely a symptom of comorbid disorders.

Predicting welding distortion in a panel structure with longitudinal stiffeners using inherent deformations obtained by inverse analysis method.

Science.gov (United States)

Liang, Wei; Murakawa, Hidekazu

2014-01-01

Welding-induced deformation not only negatively affects dimension accuracy but also degrades the performance of product. If welding deformation can be accurately predicted beforehand, the predictions will be helpful for finding effective methods to improve manufacturing accuracy. Till now, there are two kinds of finite element method (FEM) which can be used to simulate welding deformation. One is the thermal elastic plastic FEM and the other is elastic FEM based on inherent strain theory. The former only can be used to calculate welding deformation for small or medium scale welded structures due to the limitation of computing speed. On the other hand, the latter is an effective method to estimate the total welding distortion for large and complex welded structures even though it neglects the detailed welding process. When the elastic FEM is used to calculate the welding-induced deformation for a large structure, the inherent deformations in each typical joint should be obtained beforehand. In this paper, a new method based on inverse analysis was proposed to obtain the inherent deformations for weld joints. Through introducing the inherent deformations obtained by the proposed method into the elastic FEM based on inherent strain theory, we predicted the welding deformation of a panel structure with two longitudinal stiffeners. In addition, experiments were carried out to verify the simulation results.

Nonlinear longitudinal dynamics studies at the ALS

International Nuclear Information System (INIS)

Byrd, J.M.; Cheng, W.-H.; De Santis, S.; Li, D.; Stupakov, G.; Zimmermann, F.

1999-01-01

We present a summary of results for a variety of studies of nonlinear longitudinal dynamics in the Advanced Light Source, an electron storage ring. These include observation of decoherence at injection, decay of an injected beam, forced synchrotron oscillations and diffusion from one bunch to the next. All of the measurements were made using a dual-scan streak camera which allowed the real-time observation of the longitudinal distribution of the electron beam

The Longitudinal Causal Directionality between Body Image Distress and Self-Esteem among Korean Adolescents: The Moderating Effect of Relationships with Parents

Science.gov (United States)

Park, Woochul; Epstein, Norman B.

2013-01-01

This study examined the longitudinal relationship between self-esteem and body image distress, as well as the moderating effect of relationships with parents, among adolescents in Korea, using nationally representative prospective panel data. Regarding causal direction, the findings supported bi-directionality for girls, but for boys the…

Long-term effects of parental divorce timing on depression: A population-based longitudinal study.

Science.gov (United States)

Chun, Sung-Youn; Jang, Suk-Yong; Choi, Jae-Woo; Shin, Jaeyong; Park, Eun-Cheol

2016-09-08

We examined the long-term effects of parental divorce timing on depression using longitudinal data from the Korean Welfare Panel Study. Depression symptoms were measured using the 11 items of Center for Epidemiologic Scale for Depression (CES-D-11), and we categorized parental divorce timing into 'early childhood', 'adolescent' and 'none'. Although participants who experienced parental divorce during adolescence exhibited a significantly higher CES-D-11 score (p = .0468), 'early childhood' participants displayed the most increased CES-D-11 score compared to the control group (p = .0007). Conversely, among participants who were unsatisfied with their marriage, those who experienced parental divorce in early childhood showed lower CES-D-11 scores, while 'adolescent period' participants exhibited significantly higher CES-D-11 scores (p = .0131). We concluded that timing of parental divorce exerts substantial yet varied effects on long-term depression symptoms and future marriage satisfaction. © The Author(s) 2016.

A Longitudinal Examination of Childhood Maltreatment and Adolescent Obesity: Results from the National Longitudinal Study of Adolescent Health (AddHealth) Study

Science.gov (United States)

Shin, Sunny Hyucksun; Miller, Daniel P.

2012-01-01

Objectives: We sought to explore the association between childhood maltreatment (e.g., neglect, physical and sexual abuse) and longitudinal growth trajectories of body mass index (BMI) from adolescence to young adulthood. Methods: We used latent curve modeling to examine data from the National Longitudinal Study of Adolescent Health (N = 8,471),…

Sistem Panel Kinerja Untuk Program Studi Sarjana Berbasis BAN PT

Directory of Open Access Journals (Sweden)

Agus Prasetyo Utomo

2016-01-01

Full Text Available Study program need to do monitoring and continuously measurements of performance to ensure achievement the goals set of its. The process of performance requires monitoring data and information was taken from all parts of the organization. The purpose of this research is to build a panel system performance (performance dashboard that can be used to help measure the performance of undergraduate degree courses based on BAN PT in order of quality assurance in higher education. The results of performance monitoring will be delivered to the parties concerned, efficiently and effectively. Panel System (Dashboard is a tool to present information at a glance. Dashboard inform using Key Performance Indicators (KPI an effective presentation media. KPIs are used in the construction panel system performance of these courses entirely using the instruments of the National Accreditation of Higher Education. The methodology can be applied either on a case study of the development of dashboards to support the efforts of quality assurance courses at the Stikubank University Semarang. This study emphasizes how the application is to provide easy information to Head of study program, Dean of faculty, Rector and Vice Rector of university to the achievement of the quality of undergraduate study program.   Keywords: Performance Dashboard; Key Performance Indicators; Accreditation.

Panel 3 Studies in Childhood, Chuldren's Culture and Play Culture

DEFF Research Database (Denmark)

Toft, Herdis

A presentation of the collected Works of Flemming Mouritsen as published in "Mouritsen's Metode'. Herdis Toft as Panel Chair introduces the publication and also the panel of 6 researchers discussing his influence in the field.......A presentation of the collected Works of Flemming Mouritsen as published in "Mouritsen's Metode'. Herdis Toft as Panel Chair introduces the publication and also the panel of 6 researchers discussing his influence in the field....

A longitudinal mediation analysis of the effect of negative-self-schemas on positive symptoms via negative affect.

Science.gov (United States)

Jaya, E S; Ascone, L; Lincoln, T M

2018-06-01

Cognitive models postulate that negative-self-schemas (NSS) cause and maintain positive symptoms and that negative affect mediates this link. However, only few studies have tested the temporal mediation claim systematically using an appropriate design. A longitudinal cohort design in an online community sample (N = 962) from Germany, Indonesia, and the USA was used. NSS, negative affect and positive symptoms were measured at four time-points (T0-T3) over a 1-year period. Cross-lagged panel and longitudinal mediation analyses with structural equation modeling were used to test the temporal mediation. Independent cross-lagged panel models showed a significant unidirectional longitudinal path from NSS to positive symptoms (T2-T3, β = 0.18, p negative affect (T0-T1, γ = 0.14, p negative affect at T1 and T2 to positive symptoms at T3 (unstandardized indirect effect coefficient = 0.020, p affective pathway from NSS to positive symptoms via negative affect. Specifically, our data indicate that NSS and negative affect influence each other and build up over the course of several months before leading on to positive symptoms. We conclude that interrupting this process by targeting NSS and negative affect early in the process could be a promising strategy to prevent the exacerbation of positive symptoms.

A Power Case Study for Monocrystalline and Polycrystalline Solar Panels in Bursa City, Turkey

Directory of Open Access Journals (Sweden)

Ayşegül Taşçıoğlu

2016-01-01

Full Text Available It was intended to reveal the time dependent power generation under different loads for two different solar panels under the conditions of Bursa province in between August 19 and 25, 2014. The testing sets include solar panels, inverter, multimeter, accumulator, regulator, pyranometer, pyrheliometer, temperature sensor, and datalogger. The efficiency of monocrystalline and polycrystalline solar panels was calculated depending on the climatic data’s measurements. As the result of the study, the average performances of monocrystalline and polycrystalline panels are 42.06 and 39.80 Wh, respectively. It was seen that 87.14 W instantaneous power could be obtained from monocrystalline solar panel and that 80.17 W instantaneous power could be obtained from polycrystalline solar panel under maximum total radiation (1001.13 W/m2. Within this frame, it was determined that monocrystalline solar panel is able to operate more efficiently under the conditions of Bursa compared to polycrystalline solar panel. When the multivariate correlations coefficients were examined statistically, a significant relationship in positive direction was detected between total and direct radiation and ambient temperature on energy generation from monocrystalline and polycrystalline panel.

The role of personality in health care use: Results of a population-based longitudinal study in Germany.

Science.gov (United States)

Hajek, André; Bock, Jens-Oliver; König, Hans-Helmut

2017-01-01

To determine the role of personality in health care use longitudinally. Data were derived from the German Socio-Economic Panel (GSOEP), a nationally representative, longitudinal cohort study of German households starting in 1984. Concentrating on the role of personality, we used data from the years 2005, 2009 and 2013. Personality was measured by using the GSOEP Big Five Inventory (BFI-S). Number of physician visits in the last 3 months and hospital stays in the last year were used as measures of health care use. Adjusting for predisposing factors, enabling resources, and need factors, fixed effects regressions revealed that physician visits increased with increasing neuroticism, whereas extraversion, openness to experience, agreeableness and conscientiousness did not affect physician visits in a significant way. The effect of self-rated health on physician visits was significantly moderated by neuroticism. Moreover, fixed effects regressions revealed that the probability of hospitalization in the past year increased with increasing extraversion, whereas the other personality factors did not affect this outcome measure significantly. Our findings suggest that changes in neuroticism are associated with changes in physician visits and that changes in extraversion are associated with the probability of hospitalization. Since recent studies have shown that treatments can modify personality traits, developing interventional strategies should take into account personality factors. For example, efforts to intervene in changing neuroticism might have beneficial effects for the healthcare system.

The role of personality in health care use: Results of a population-based longitudinal study in Germany.

Directory of Open Access Journals (Sweden)

André Hajek

Full Text Available To determine the role of personality in health care use longitudinally.Data were derived from the German Socio-Economic Panel (GSOEP, a nationally representative, longitudinal cohort study of German households starting in 1984. Concentrating on the role of personality, we used data from the years 2005, 2009 and 2013. Personality was measured by using the GSOEP Big Five Inventory (BFI-S. Number of physician visits in the last 3 months and hospital stays in the last year were used as measures of health care use.Adjusting for predisposing factors, enabling resources, and need factors, fixed effects regressions revealed that physician visits increased with increasing neuroticism, whereas extraversion, openness to experience, agreeableness and conscientiousness did not affect physician visits in a significant way. The effect of self-rated health on physician visits was significantly moderated by neuroticism. Moreover, fixed effects regressions revealed that the probability of hospitalization in the past year increased with increasing extraversion, whereas the other personality factors did not affect this outcome measure significantly.Our findings suggest that changes in neuroticism are associated with changes in physician visits and that changes in extraversion are associated with the probability of hospitalization. Since recent studies have shown that treatments can modify personality traits, developing interventional strategies should take into account personality factors. For example, efforts to intervene in changing neuroticism might have beneficial effects for the healthcare system.

Longitudinal relations between adolescents' self-esteem and prosocial behavior toward strangers, friends and family.

Science.gov (United States)

Fu, Xinyuan; Padilla-Walker, Laura M; Brown, Michael N

2017-06-01

The present study examined age-trends and longitudinal bidirectional relations in self-esteem and prosocial behavior toward strangers, friends, and family over a four-year time period (age 11 to 14). A total of 681 adolescents were recruited in the United States (51% girls, 28% single parent families). A longitudinal panel model was conducted and the results showed that adolescent self-esteem was associated longitudinally with subsequent prosocial behavior toward strangers, and earlier prosocial behavior toward strangers promoted subsequent self-esteem. There were no such bidirectional relations between self-esteem and prosocial behavior toward friends and family. Findings also highlight the complexity of adolescent development of selfesteem and the multidimensional nature of prosocial behavior. Discussion focuses on understanding the dynamic interplay between adolescent selfesteem and prosocial behavior. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Rationales, design and recruitment for the Elfe longitudinal study

Directory of Open Access Journals (Sweden)

Salines Georges

2009-09-01

Full Text Available Abstract Background Many factors act simultaneously in childhood to influence health status, life chances and well being, including pre-birth influences, the environmental pollutants of early life, health status but also the social influences of family and school. A cohort study is needed to disentangle these influences and explore attribution. Methods Elfe will be a nationally representative cohort of 20 000 children followed from birth to adulthood using a multidisciplinary approach. The cohort will be based on the INSEE Permanent Demographic Panel (EDP established using census data and civil records. The sample size has been defined in order to match the representativeness criteria and to obtain some prevalence estimation, but also to address the research area of low exposure/rare effects. The cohort will be based on repeated surveys by face to face or phone interview (at birth and each year as well as medical interview (at 2 years and examination (at 6 years. Furthermore, biological samples will be taken at birth to evaluate the foetal exposition to toxic substances, environmental sensors will be placed in the child's homes. Pilot studies have been initiated in 2007 (500 children with an overall acceptance rate of 55% and are currently under progress, the 2-year survey being carried out in October this year. Discussion The longitudinal study will provide a unique source of data to analyse the development of children in their environment, to study the various factors interacting throughout the life course up to adulthood and to determine the impact of childhood experience on the individual's physical, psychological, social and professional development.

Consumer panel study on elderly people's wishes concerning services.

Science.gov (United States)

Valkila, Noora; Litja, Heli; Aalto, Leena; Saari, Arto

2010-01-01

This study informs on the wishes and needs of elderly people themselves regarding services for the elderly. The data for the study were gathered using a consumer panel method. Elderly people desire assistance in heavy cleaning chores, in outdoor activities and in carrying out their personal business. Elderly people felt that there should be more recreational services available. Elderly people link aging with feelings of insecurity and loneliness. Becoming a service user for the first time is felt to be a very difficult step to take, and so this decision is postponed as long as possible. The elderly people desire a service for assessing their individual service needs in an organized, expert and objective fashion. The study indicates that elderly people value the human contact gained through service provision. The consumer panel method for collecting data was successful. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Ageing tests study on wood-based sandwich panels

Directory of Open Access Journals (Sweden)

Mateo, Raquel

2011-12-01

Full Text Available Composite lightweight wood panels are being increasingly used in construction in Spain. Their growing use should be accompanied by necessary guarantees based on studies of their properties. As it is prescriptive and in addition to others tests, in the present work is examinated the durability of these panels when exposed to the climatic conditions, a characteristic of great importance for wood products, according to Guide ETAG 016, the current standard defining the ageing tests to be used. However, due to the use class of this material, there are indications that the testing outlined in this Guide is inappropriate for assessing the ageing of wood-based sandwich panels. Alternative tests are here proposed that recreate rather better the real conditions under which these products are used. Covering the samples in a waterproof sheeting permeable to the outward movement of water vapour, which is in fact used in the installation, provided the best procedure for testing these panels.

Los paneles sándwich de madera son un producto de creciente aplicación en la edificación de nuestro país. Este ascendente uso del material debe estar acompañado de las garantías necesarias avaladas por un estudio previo de sus prestaciones. Como es preceptivo y entre otros, se evalúa su durabilidad frente a las condiciones climatológicas, clave en los productos derivados de la madera, acorde a la normativa actual definida con tal fin, la Guía ETAG 016. Sin embargo, debido a la clase de uso del material, se ha detectado que dicha normativa tal y como está concebida no es capaz de valorar su envejecimiento adecuadamente. En este trabajo se proponen ensayos alternativos al establecido tras exhaustivos análisis que recrean las condiciones reales de uso y más acordes a los productos de madera. Se concluye que la incorporación de una lámina impermeable pero permeable al vapor de agua hacia el exterior, como las utilizadas en el montaje, aportan el mejor

Longitudinal development of number line estimation and mathematics performance in primary school children.

Science.gov (United States)

Friso-van den Bos, Ilona; Kroesbergen, Evelyn H; Van Luit, Johannes E H; Xenidou-Dervou, Iro; Jonkman, Lisa M; Van der Schoot, Menno; Van Lieshout, Ernest C D M

2015-06-01

Children's ability to relate number to a continuous quantity abstraction visualized as a number line is widely accepted to be predictive of mathematics achievement. However, a debate has emerged with respect to how children's placements are distributed on this number line across development. In the current study, different models were applied to children's longitudinal number placement data to get more insight into the development of number line representations in kindergarten and early primary school years. In addition, longitudinal developmental relations between number line placements and mathematical achievement, measured with a national test of mathematics, were investigated using cross-lagged panel modeling. A group of 442 children participated in a 3-year longitudinal study (ages 5-8 years) in which they completed a number-to-position task every 6 months. Individual number line placements were fitted to various models, of which a one-anchor power model provided the best fit for many of the placements at a younger age (5 or 6 years) and a two-anchor power model provided better fit for many of the children at an older age (7 or 8 years). The number of children who made linear placements also grew with age. Cross-lagged panel analyses indicated that the best fit was provided with a model in which number line acuity and mathematics performance were mutually predictive of each other rather than models in which one ability predicted the other in a non-reciprocal way. This indicates that number line acuity should not be seen as a predictor of math but that both skills influence each other during the developmental process. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Experimental study on behavior of RC panels covered with steel plates subjected to missile impact

International Nuclear Information System (INIS)

Jun Hashimoto; Katsuki Takiguchi; Koshiro Nishimura; Kazuyuki Matsuzawa; Mayuko Tsutsui; Yasuhiro Ohashi; Isao Kojima; Haruhiko Torita

2005-01-01

This paper describes an experimental study on the behavior of concrete panels with steel plate subjected to missile impact. Two tests were carried out, divided in accordance with the types of projectile, non-deformable and deformable. In all, 40 specimens of 750 mm square were prepared. The panel specimen was suspended vertically by two steel wire ropes to allow free movement after projectile impact, and was subjected to a projectile. As a result, it is confirmed that a RC panel with steel plate on its back side has higher impact resistance performance than a RC panel and that thickness of concrete panel, thickness of steel plate and the impact velocity of the projectile have a great effect on the failure modes of steel concrete panels. Moreover, based on the experimental results, the quantitative evaluation method for impact resistance performance of RC panels covered with steel plates is examined. The formula for perforation velocity of a half steel concrete panel, proposed in accordance with the bulging height, is effective to evaluate the impact resistance performance of RC panels with steel plates. (authors)

A Longitudinal Study of Usability in Health Care

DEFF Research Database (Denmark)

Kjeldskov, Jesper; Skov, Mikael B.; Stage, Jan

2010-01-01

We report from a longitudinal laboratory-based usability evaluation of a health care information system. The purpose of the study was to inquire into the nature of usability problems experienced by novice and expert users, and to see to what extend usability problems of a health care information...... system may or may not disappear over time, as the nurses get more familiar with it-if time heals poor design? As our method for studying this, we conducted a longitudinal study with two key studies. A usability evaluation was conducted with novice users when an electronic patient record system was being......, we discuss implications for evaluating usability in health care....

Behaviour of partially composite precast concrete sandwich panels under flexural and axial loads

Science.gov (United States)

Tomlinson, Douglas George

-slip behaviour of the shear connection and to analyze the full panel's flexural and axial response to determine the longitudinal shear force transferred between wythes and account for partial composite behavior. The models were validated against experiments and used to conduct a parametric study. Among several interesting findings, the study demonstrated how composite action increases with the slenderness of axially loaded panels.

Association between interpersonal trust, reciprocity, and suicidal behaviors: A longitudinal cohort study in South Korea.

Science.gov (United States)

Kim, Ja Young; Yoon, Jaehong; Kim, Myoung-Hee; Kim, Seung-Sup

2017-06-01

While a growing body of evidence suggest that social capital including interpersonal trust and reciprocity might be associated with mental health outcomes, few studies have explored the relationship with suicidal behaviors. This research examined the prospective association between interpersonal trust and reciprocity and suicidal behaviors using the Korea Welfare Panel Study, a nationally representative longitudinal cohort dataset in South Korea. Interpersonal trust and reciprocity were assessed at the 7th wave of the survey (2012), and each measure was classified into two categories (low vs. high). Experience of suicidal ideation, planning, and attempt was assessed between the 8th (2013) and 10th wave (2015) of the surveys. After adjusting for confounders including lifetime experience of suicidal behaviors at the 7th wave of the survey (2012) as well as socio-demographic information, the low interpersonal trust group was more likely to experience suicidal ideation (OR: 1.30, 95% CI: 1.11-1.53) compared to the high interpersonal trust group whereas no statistically significant association was observed in the reciprocity analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

A longitudinal study on psychosocial causes and consequences of Internet gaming disorder in adolescence.

Science.gov (United States)

Wartberg, Lutz; Kriston, Levente; Zieglmeier, Matthias; Lincoln, Tania; Kammerl, Rudolf

2018-04-06

In 2013, Internet gaming disorder (IGD) was incorporated in the current version of the DSM-5. IGD refers to a problematic use of video games. Longitudinal studies on the etiology of IGD are lacking. Furthermore, it is currently unclear to which extent associated psychopathological problems are causes or consequences of IGD. In the present survey, longitudinal associations between IGD and adolescent and parental mental health were investigated for the first time, as well as the temporal stability of IGD. In a cross-lagged panel design study, family dyads (adolescent with a parent each) were examined in 2016 (t1) and again 1 year later (2017, t2). Overall, 1095 family dyads were assessed at t1 and 985 dyads were re-assessed at t2 with standardized measures of IGD and several aspects of adolescent and parental mental health. Data were analyzed with structural equation modeling (SEM). Male gender, a higher level of hyperactivity/inattention, self-esteem problems and IGD at t1 were predictors of IGD at t2. IGD at t1 was a predictor for adolescent emotional distress at t2. Overall, 357 out of the 985 adolescents received a diagnosis of IGD at t1 or t2: 142 (14.4%) at t1 and t2, 100 (10.2%) only at t1, and 115 (11.7%) only at t2. Hyperactivity/inattention and self-esteem problems seem to be important for the development of IGD. We found first empirical evidence that IGD could prospectively contribute to a deterioration of adolescent mental health. Only a subgroup of affected adolescents showed IGD consistently over 1 year.

Residents’ perceptions of an integrated longitudinal curriculum: a qualitative study

Directory of Open Access Journals (Sweden)

Rebecca Lubitz

2015-12-01

Conclusions: This study suggests that an integrated longitudinalized family medicine block training model has the potential to support the principles of a longitudinal integrated competency-based curriculum to effectively prepare residents for family medicine practice.

Fostering marginalized youths' political participation: longitudinal roles of parental political socialization and youth sociopolitical development.

Science.gov (United States)

Diemer, Matthew A

2012-09-01

This study examines the roles of parental political socialization and the moral commitment to change social inequalities in predicting marginalized youths' (defined here as lower-SES youth of color) political participation. These issues are examined by applying structural equation modeling to a longitudinal panel of youth. Because tests of measurement invariance suggested racial/ethnic heterogeneity, the structural model was fit separately for three racial/ethnic groups. For each group, parental political socialization: discussion predicted youths' commitment to produce social change and for two groups, longitudinally predicted political participation. This study contributes to the literature by examining civic/political participation among disparate racial/ethnic groups, addresses an open scholarly question (whether youths' commitment to create social change predicts their "traditional" participation), and emphasizes parents' role in fostering marginalized youths' civic and political participation.

A Power Case Study for Monocrystalline and Polycrystalline Solar Panels in Bursa City, Turkey

OpenAIRE

Taşçıoğlu, Ayşegül; Taşkın, Onur; Vardar, Ali

2016-01-01

It was intended to reveal the time dependent power generation under different loads for two different solar panels under the conditions of Bursa province in between August 19 and 25, 2014. The testing sets include solar panels, inverter, multimeter, accumulator, regulator, pyranometer, pyrheliometer, temperature sensor, and datalogger. The efficiency of monocrystalline and polycrystalline solar panels was calculated depending on the climatic data’s measurements. As the result of the study, th...

Numerical Study on the Projectile Impact Resistance of Multi-Layer Sandwich Panels with Cellular Cores

Directory of Open Access Journals (Sweden)

Liming Chen

Full Text Available Abstract The projectile impact resistance of sandwich panels with cellular cores with different layer numbers has been numerically investigated by perpendicular impact of rigid blunt projectile in ABAQUS/Explicit. These panels with corrugation, hexagonal honeycomb and pyramidal truss cores are impacted at velocities between 50 m/s and 202 m/s while the relative density ranges from 0.001 to 0.15 The effects of core configuration and layer number on projectile impact resistance of sandwich panels with cellular cores are studied. At low impact velocity, sandwich panels with cellular cores outperform the corresponding solid ones and non-montonicity between relative density and projectile resistance of sandwich panels is found and analyzed. Multiplying layer can reduce the maximum central deflection of back face sheet of the above three sandwich panels except pyramidal truss ones in high relative density. Hexagonal honeycomb sandwich panel is beneficial to increasing layer numbers in lowering the contact force and prolonging the interaction time. At high impact velocity, though corrugation and honeycomb sandwich panels are inferior to the equal-weighted solid panels, pyramidal truss ones with high relative density outperform the corresponding solid panels. Multiplying layer is not the desirable way to improve high-velocity projectile resistance.

Dead or Alive? Dealing with Unknown Eligibility in Longitudinal Surveys

Directory of Open Access Journals (Sweden)

Watson Nicole

2016-12-01

Full Text Available Longitudinal surveys follow people over time and some of these people will die during the life of the panel. Through fieldwork effort, some deaths will be reported or known, but others will be unobserved due to sample members no longer being issued to field or having inconclusive fieldwork outcomes (such as a noncontact that is not followed by a contact at a later wave. The coverage of deaths identified among sample members has flow-on implications to nonresponse correction. Using the Household, Income and Labour Dynamics in Australia (HILDA Survey, four methods are used to examine the extent of missing death reports. The first method matches the sample to the national death register. The second method uses life-expectancy tables to extrapolate the expected number of deaths among the sample with unknown eligibility. The third method is similar but models deaths from data internal to the survey. The fourth method models deaths as part of the attrition process of a longitudinal survey. The last three methods are compared to the first method and the implications for the construction of balanced panel weights and subsequent population inference are explored.

Blast response of curved carbon/epoxy composite panels: Experimental study and finite-element analysis

International Nuclear Information System (INIS)

Phadnis, V A; Roy, A; Silberschmidt, V V; Kumar, P; Shukla, A

2013-01-01

Experimental and numerical studies were conducted to understand the effect of plate curvature on blast response of carbon/epoxy composite panels. A shock-tube system was utilized to impart controlled shock loading to quasi-isotropic composite panels with differing range of radii of curvatures. A 3D Digital Image Correlation (DIC) technique coupled with high-speed photography was used to obtain out-of-plane deflection and velocity, as well as in-plane strain on the back face of the panels. Macroscopic post-mortem analysis was performed to compare yielding and deformation in these panels. A dynamic computational simulation that integrates fluid-structure interaction was conducted to evaluate the panel response in general purpose finite-element software ABAQUS/Explicit. The obtained numerical results were compared to the experimental data and showed a good correlation

Longitudinal coupled-bunch instability studies in the PS

CERN Document Server

Damerau, H

2017-01-01

The main longitudinal limitation for LHC-type beams inthe PS are coupled-bunch instabilities. A dedicated proto-typefeedbacksystemusingaFinemetcavityasalongitudinalkicker has been installed. Extensive tests with beam havebeen performed to explore the intensity reach with this feed-back. The maximum intensity with nominal longitudinalemittance at PS extraction has been measured, as well as theemittance required to keep the beam longitudinally stableat the design intensity for the High-Luminosity LHC (HL-LHC). A higher-harmonic cavity is a complementary op-tion to extend the intensity reach beyond the capabilities ofthe coupled-bunch feedback. Preliminary machine develop-ment (MD) studies operating one20MHzor one40MHzRF system as a higher harmonic at the flat-top indicate thebeneficial effect on longitudinal beam stability

Composite panel development at JPL

Science.gov (United States)

Mcelroy, Paul; Helms, Rich

1988-01-01

Parametric computer studies can be use in a cost effective manner to determine optimized composite mirror panel designs. An InterDisciplinary computer Model (IDM) was created to aid in the development of high precision reflector panels for LDR. The materials properties, thermal responses, structural geometries, and radio/optical precision are synergistically analyzed for specific panel designs. Promising panels designs are fabricated and tested so that comparison with panel test results can be used to verify performance prediction models and accommodate design refinement. The iterative approach of computer design and model refinement with performance testing and materials optimization has shown good results for LDR panels.

Simulation Study of Discharging PCM Ceiling Panels through Night - time Radiative Cooling

DEFF Research Database (Denmark)

Bourdakis, Eleftherios; Kazanci, Ongun Berk; Grossule, F.

2016-01-01

demand. In the present simulation study, the coupling of nighttime radiative cooling with PCM for cooling an office room was investigated. For cooling water through nighttime radiative cooling two types of solar panels were utilized, an unglazed solar collector and photovoltaic/thermal (PV/T) panels...... provided by the PV/T panels was 43 W/m2 for Copenhagen, while for Milan and Athens it was 36 W/m2 and 34 W/m2, respectively. The cooling power of the unglazed solar collector was negligible. Finally, the total electricity produced in Copenhagen for the simulated period was 371 kWh, while for Milan...... and increase use of renewable energy sources. The aim is that by 2020 all new buildings should be nearly zero-energy buildings. A solution that could contribute to this is the combination of photovoltaic panels for the production of electricity and phase change material (PCM) for the reduction of peak cooling...

LEIR longitudinal studies

CERN Document Server

Albright, S; Hancock, S

2017-01-01

Towards the end of 2015 and during 2016 there were exten-sive studies of longitudinal beam dynamics in LEIR aimedat improving extracted intensities. As the driving source oflosses early in the ramp was shown to be transverse spacecharge tune spread a significant improvement came fromflattening the beam profile to increase the bunching factorby offsetting the RF frequency from the beam revolution fre-quency. Further benefits were provided by modulating theRF frequency during capture, leading to emittance blow-upand improved reproducibility. The use of two RF cavitiesduring operation was studied to try and further increase thecaptured emittance, however after careful alignment of theRF it was found that a hard limit in the bunch heigh of approx-imately 7 MeV exists. Due to the acceptance limit there wasno operational benefit to using both cavities simultaneously

Comparison of solar panel models for grid integration studies

NARCIS (Netherlands)

Brito, E.M.S.; Cupertino, A.F.; Carlette, L.P; Filho, D.O.; Oliveira, D.; Pereira, H.A; Ribeiro, P.F.

2012-01-01

Photovoltaic systems are highly dependent on climatic conditions in which they are submitted. The incident solar irradiance and temperature are the main factors impacting on the power generated by a solar panel. This paper presents three different models of a solar panel and compare, through

Aging Baby Boomers and the Rising Cost of Chronic Back Pain: Secular Trend Analysis of Longitudinal Medical Expenditures Panel Survey Data for Years 2000 to 2007

Science.gov (United States)

Smith, Monica; Davis, Matthew A.; Stano, Miron; Whedon, James M.

2013-01-01

Objectives The purposes of this study were to analyze data from the longitudinal Medical Expenditures Panel Survey (MEPS) to evaluate the impact of an aging population on secular trends in back pain and chronicity and to provide estimates of treatment costs for patients who used only ambulatory services. Methods Using the MEPS 2-year longitudinal data for years 2000 to 2007, we analyzed data from all adult respondents. Of the total number of MEPS respondent records analyzed (N = 71 838), we identified 12 104 respondents with back pain and further categorized 3842 as chronic cases and 8262 as nonchronic cases. Results Secular trends from the MEPS data indicate that the prevalence of back pain has increased by 29%, whereas chronic back pain increased by 64%. The average age among all adults with back pain increased from 45.9 to 48.2 years; the average age among adults with chronic back pain increased from 48.5 to 52.2 years. Inflation-adjusted (to 2010 dollars) biennial expenditures on ambulatory services for chronic back pain increased by 129% over the same period, from $15.6 billion in 2000 to 2001 to $35.7 billion in 2006 to 2007. Conclusion The prevalence of back pain, especially chronic back pain, is increasing. To the extent that the growth in chronic back pain is caused, in part, by an aging population, the growth will likely continue or accelerate. With relatively high cost per adult with chronic back pain, total expenditures associated with back pain will correspondingly accelerate under existing treatment patterns. This carries implications for prioritizing health policy, clinical practice, and research efforts to improve care outcomes, costs, and cost-effectiveness and for health workforce planning. PMID:23380209

Proactivity, job characteristics, and engagement : a longitudinal study

NARCIS (Netherlands)

Dikkers, Josje S. E.; Jansen, Paul G. W.; de Lange, Annet H.; Vinkenburg, Claartje J.; Kooij, Dorien

2010-01-01

Purpose - This paper sets out to examine proactive personality in relation to job demands, job resources and engagement. Design/methodology/approach - The current study employed a two-wave complete panel study among 794 Dutch government employees. Based upon the Job Demands-Resources (ID-R) model,

The concurrent and longitudinal relationships between adolescents' use of social network sites and their social self-esteem.

Science.gov (United States)

Valkenburg, Patti M; Koutamanis, Maria; Vossen, Helen G M

2017-11-01

The first aim of this study was to investigate the concurrent and longitudinal relationships between adolescents' use of social network sites (SNSs) and their social self-esteem. The second aim was to investigate whether the valence of the feedback that adolescents receive on SNSs can explain these relationships. We conducted a three-wave panel study among 852 pre- and early adolescents (10-15 years old). In line with earlier research, we found significant concurrent correlations between adolescents' SNS use and their social self-esteem in all three data waves. The longitudinal results only partly confirmed these concurrent findings: Adolescents' initial SNS use did not significantly influence their social self-esteem in subsequent years. In contrast, their initial social self-esteem consistently influenced their SNS use in subsequent years. The valence of online feedback from close friends and acquaintances explained the concurrent relationship between SNS use and social self-esteem, but not the longitudinal relationship. Results are discussed in terms of their methodological and theoretical implications.

Late Career Decision-Making: A Qualitative Panel Study

NARCIS (Netherlands)

Wilmar Schaufeli; Annet de Lange; Juhani Ilmarinen; Per Erik Solem; Trude Furunes; Reidar Mykletun; Astri Syse

2015-01-01

The aim of this longitudinal qualitative interview study (3 waves of interviews) was to examine the nature of older workers’ late career decision-making processes, including the main drivers and obstacles for prolonging working life or retiring. Late career decision-making is regarded as a process

Methodological study about the chromatic reintegration of a set of tile panels

Directory of Open Access Journals (Sweden)

Maria do Castelo Abreu Coutinho

2018-01-01

Full Text Available With this text we intend to present a study which focuses on a set of tile panels of unknown provenance and authorship, belonging to the Museu Nacional do Azulejo collection, Lisbon, Portugal, from the late seventeenth century. The painting technique makes it unique and justifies the intention of the museum to prepare one of them for permanent exhibition, despite the figurative lacunae. Therefore, among the conservation and restoration treatments to be carried out on this panel, the chromatic reintegration proved to be the biggest challenge. Based on an engraving of Gilles Rousselet (1610-1686, probably the one that served as inspiration for the artist who painted the panel, several proposals will be made in order to find a solution.

Are Sibling Relationships Protective? A Longitudinal Study

Science.gov (United States)

Gass, Krista; Jenkins, Jennifer; Dunn, Judy

2007-01-01

Background: Although the protective effects of familial and parental support have been studied extensively in the child psychopathology literature, few studies have explored the protective quality of positive sibling relationships. Methods: A two-wave longitudinal design was used to examine the protective effect of positive sibling relationships…

Mode system effects in an online panel study : Comparing a probability-based online panel with two face-to-face reference surveys

NARCIS (Netherlands)

Struminskaya, Bella; de Leeuw, E.D.; Kaczmirek, Lars

2015-01-01

One of the methods for evaluating online panels in terms of data quality is comparing the estimates that the panels provide with benchmark sources. For probability-based online panels, high-quality surveys or government statistics can be used as references. If differences among the benchmark and the

Financial Development and Output Growth: A Panel Study for Asian Countries

Directory of Open Access Journals (Sweden)

Sangjoon Jun

2012-03-01

Full Text Available This paper investigates the relationship between financial markets and output growth for a panel of 27 Asian countries over 1960-2009. It utilizes the recently-developed panel cointegration techniques to test and estimate the long-run equilibrium relationship between real GDP and financial development proxies. Real GDP and financial development variables are found to have unit roots and to be cointegrated, based on various panel unit root tests and panel cointegration tests. We find that there is a statistically significant positive bi-directional cointegrating relationship between financial development and output growth by three distinct methods of panel cointegration estimation. Empirical findings suggest that financial market development promotes output growth and in turn output growth stimulates further financial development.

Longitudinal tracking studies for a high intensity proton synchrotron

International Nuclear Information System (INIS)

Lessner, E.; Cho, Y.; Harkay, K.; Symon, K.

1995-01-01

Results from longitudinal tracking studies for a high intensity proton synchrotron designed for a 1-MW spallation source are presented. The machine delivers a proton beam of 0.5 mA time-averaged current at a repetition rate of 30 Hz. The accelerator is designed to have radiation levels that allow hands-on-maintenance. However, the high beam intensity causes strong space charge fields whose effects may lead to particle loss and longitudinal instabilities. The space charge fields modify the particle distribution, distort the stable bucket area and reduce the rf linear restoring force. Tracking simulations were conducted to analyze the space charge effects on the dynamics of the injection and acceleration processes and means to circumvent them. The tracking studies led to the establishment of the injected beam parameters and rf voltage program that minimized beam loss and longitudinal instabilities. Similar studies for a 10-GeV synchrotron that uses the 2-GeV synchrotron as its injector are also discussed

The associations between TV viewing, food intake, and BMI. A prospective analysis of data from the Longitudinal Study of Australian Children.

Science.gov (United States)

Fuller-Tyszkiewicz, Matthew; Skouteris, Helen; Hardy, Louise L; Halse, Christine

2012-12-01

Despite cross-sectional evidence of a link between TV viewing and BMI in early childhood, there has been limited longitudinal exploration of this relationship. The aim of the present study was to explore the potential bi-directionality of the relationship between TV viewing and child BMI. A secondary aim was to evaluate whether this relationship is mediated by dietary intake. Parents of 9064 children (4724 recruited at birth, 4340 recruited at age 4) from the Longitudinal Study of Australian Children (LSAC) completed measures of their child's dietary intake and TV viewing habits at three equidistant time points, separated by 2years. Objective measures of height and weight were also obtained at each time point to calculate BMI. Cross-lagged panel analyses were conducted to evaluate potential bi-directional associations between TV viewing and child BMI, and to evaluate mediation effects of dietary intake for this relationship. Our longitudinal findings suggest that the relationship between TV viewing and BMI is bi-directional: Individuals who watch TV are more likely to gain weight, and individuals who are heavier are also more likely to watch TV. Interestingly, dietary intake mediated the BMI-TV viewing relationship for the older children, but not for the birth cohort. Present findings suggest that sedentary behaviours, particularly when coupled with unhealthy dietary habits, constitute a significant risk factor for excessive weight gain in early childhood. Interventions targeted at helping parents to develop healthy TV viewing and eating habits in their young children are clearly warranted. Copyright © 2012 Elsevier Ltd. All rights reserved.

Collaborative Knowledge-Building: A Longitudinal Study

Science.gov (United States)

Li, Qing

2009-01-01

The focus of this paper is on knowledge-building in a technology-supported learning environment in higher education through a longitudinal study of a graduate course from 2003 to 2007. The primary question is: how do learning conditions designed into a graduate course contribute to collaborative knowledge building? In particular, two major…

The 2008 financial crisis: Changes in social capital and its association with psychological wellbeing in the United Kingdom - A panel study.

Science.gov (United States)

Lindström, Martin; Giordano, Giuseppe N

2016-03-01

The global financial crisis of 2008 was described by the IMF as the worst recession since the Great Depression. This historic event provided the backdrop to this United Kingdom (UK) longitudinal study of changes in associations between social capital and psychological wellbeing. Past longitudinal studies have reported that the presence of social capital may buffer against adverse mental health outcomes. This study adds to existing literature by employing data from the British Household Panel Survey and tracking the same individuals (N = 11,743) pre- and immediately post-crisis (years 2007-09). With longitudinal, multilevel logistic regression modelling, we aimed to compare the buffering effects of individual-level social capital (generalised trust and social participation) against worse psychological wellbeing (GHQ-12) during and immediately after the 2008 financial crisis. After comparing the same individuals over time, results showed that stocks of social capital (generalised trust) were significantly depleted across the UK during the crisis, from 40% trusting others in 2007 to 32% in 2008. Despite this drop, the buffering effect of trust against worse psychological wellbeing was pronounced in 2008; those not trusting had an increased risk of worse psychological wellbeing in 2008 compared with the previous year in fully adjusted models (OR = 1.49, 95% CI (1.34-1.65). Levels of active participation increased across the timeframe of this study but were not associated with psychological health. From our empirical evidence, decision makers should be made aware of how events such as the crisis (and the measures taken to counter its effects) could negatively impact on a Nation's trust levels. Furthermore, past research implies that the positive effects of trust on psychological wellbeing evident in this study may only be short-term; therefore, decision makers should also prioritise policies that restore trust levels to improve the psychological wellbeing of the

Longitudinal, reciprocal effects of social skills and achievement from kindergarten to eighth grade.

Science.gov (United States)

Caemmerer, Jacqueline M; Keith, Timothy Z

2015-08-01

Previous research suggests that students' social skills and achievement are interrelated, and some findings support bi-directional effects between the two constructs. The purpose of this research study was to estimate the possible longitudinal and reciprocal effects of social skills and achievement for kindergarten through eighth grade students. Data from the Early Childhood Longitudinal Study program were analyzed; teachers' ratings of students' social skills and students' standardized math and reading achievement performance were collected 4 and 5 times, respectively. Latent variable structural equation modeling was used to test a panel model of reciprocal, longitudinal effects of social skills and achievement. The results suggest that the effects of students' social skills and achievement are bi-directional, but the effects of students' achievement on their later social skills are stronger than the effects of social skills on achievement. The significant effects of students' social skills on their later achievement are mostly indirect. These findings suggest that the future social skills of students who struggle academically may be of particular concern to educators, and intervention and prevention efforts aimed to address both social and achievement skills may help remediate the other skill in the future. Copyright © 2015 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Lightweight panel study 2012: Perceptions and usage by North American wood products manufacturers

Science.gov (United States)

Urs Buehlmann; Matt Bumgardner; Karl D. Forth

2012-01-01

Lightweight panels (panels made of two thin panels on the outside and a lightweight material in the core) can offer enhanced performance, reduced material use, and new design opportunities over traditional types of panels. Opportunities exist for the adoption of lightweight panels by the secondary wood industry in North America, as 62 percent of respondents to a recent...

Perceived classism and its relation with socioeconomic status, health, health behaviours and perceived inferiority: the Dutch Longitudinal Internet Studies for the Social Sciences (LISS) panel.

Science.gov (United States)

Simons, Audrey M W; Koster, Annemarie; Groffen, Daniëlle A I; Bosma, Hans

2017-05-01

Classism might be the downside of the prevailing ideologies of individual responsibility for success. However, since studies into perceived classism have mainly been qualitative, little is known about its association with socioeconomic status, health, health behaviours and perceived inferiority, especially in more egalitarian countries. This study, therefore, examined the associations of perceived classism with socioeconomic status, health, health behaviours and perceived inferiority. We used cross-sectional data (2012/2013) from the Dutch Longitudinal Internet Studies for the Social Sciences (LISS) (n = 1540; age 16-90; 46.9 % men). We found that classism was perceived by 18.2 % of the participants, with the lowest income and occupation group most likely to perceive classism (22.0 and 27.5 %, respectively). Perceived classism was significantly associated with poor health (e.g. self-rated health OR = 2.44, 95 % CI = 1.76-3.38) and feelings of inferiority (e.g. shame OR = 4.64, 95 % CI = 3.08-6.98). No significant associations were found with health behaviours. To further examine the role of perceived classism for socioeconomic differences in health and its association with country-level socioeconomic inequalities, prevailing ideologies, and objective opportunities for social mobility, we recommend more longitudinal and international studies with comparable measures of perceived classism.

Dynamic heat transfer modeling and parametric study of thermoelectric radiant cooling and heating panel system

International Nuclear Information System (INIS)

Luo, Yongqiang; Zhang, Ling; Liu, Zhongbing; Wang, Yingzi; Wu, Jing; Wang, Xiliang

2016-01-01

Highlights: • Dynamic model of thermoelectric radiant panel system is established. • The internal parameters of thermoelectric module are dynamically calculated in simulation. • Both artificial neural networks model and system model are verified through experiment data. • Optimized system structure is obtained through parametric study. - Abstract: Radiant panel system can optimize indoor thermal comfort with lower energy consumption. The thermoelectric radiant panel (TERP) system is a new and effective prototype of radiant system using thermoelectric module (TEM) instead of conventional water pipes, as heat source. The TERP can realize more stable and easier system control as well as lower initial and operative cost. In this study, an improved system dynamic model was established by combining analytical system model and artificial neural networks (ANN) as well as the dynamic calculation functions of internal parameters of TEM. The double integral was used for the calculation of surface average temperature of TERP. The ANN model and system model were in good agreement with experiment data in both cooling and heating mode. In order to optimize the system design structure, parametric study was conducted in terms of the thickness of aluminum panel and insulation, as well as the arrangement of TEMs on the surface of radiant panel. It was found through simulation results that the optimum thickness of aluminum panel and insulation are respectively around 1–2 mm and 40–50 mm. In addition, TEMs should be uniformly installed on the surface of radiant panel and each TEM should stand at the central position of a square-shaped typical region with length around 0.387–0.548 m.

Inclusion of Population-specific Reference Panel from India to the 1000 Genomes Phase 3 Panel Improves Imputation Accuracy.

Science.gov (United States)

Ahmad, Meraj; Sinha, Anubhav; Ghosh, Sreya; Kumar, Vikrant; Davila, Sonia; Yajnik, Chittaranjan S; Chandak, Giriraj R

2017-07-27

Imputation is a computational method based on the principle of haplotype sharing allowing enrichment of genome-wide association study datasets. It depends on the haplotype structure of the population and density of the genotype data. The 1000 Genomes Project led to the generation of imputation reference panels which have been used globally. However, recent studies have shown that population-specific panels provide better enrichment of genome-wide variants. We compared the imputation accuracy using 1000 Genomes phase 3 reference panel and a panel generated from genome-wide data on 407 individuals from Western India (WIP). The concordance of imputed variants was cross-checked with next-generation re-sequencing data on a subset of genomic regions. Further, using the genome-wide data from 1880 individuals, we demonstrate that WIP works better than the 1000 Genomes phase 3 panel and when merged with it, significantly improves the imputation accuracy throughout the minor allele frequency range. We also show that imputation using only South Asian component of the 1000 Genomes phase 3 panel works as good as the merged panel, making it computationally less intensive job. Thus, our study stresses that imputation accuracy using 1000 Genomes phase 3 panel can be further improved by including population-specific reference panels from South Asia.

Burnout development among dentists : a longitudinal study

NARCIS (Netherlands)

te Brake, H.; Smits, N.; Wicherts, J.M.; Gorter, R.C.; Hoogstraten, J.

2008-01-01

Knowledge on the development of burnout among dentists is important for purposes of prevention and intervention. Using a two-wave longitudinal design, this study examined the chronological sequence of the three dimensions of the Maslach Burnout Inventory: emotional exhaustion; depersonalization; and

Seismic hazard analysis. Review panel, ground motion panel, and feedback results

International Nuclear Information System (INIS)

Bernreuter, D.L.

1981-10-01

The Site Specific Spectra Project (SSSP) was a multi-year study funded by the U.S. Nuclear Regulatory Commission to provide estimates of the seismic hazards at a number of nuclear power plant sites in the Eastern U.S. A key element of our approach was the Peer Review Panel, which we formed in order to ensure that our use of expert opinion was reasonable. We discuss the Peer Review Panel results and provide the complete text of each member's report. In order to improve the ground motion model, an Eastern U.S. Ground Motion Model Panel was formed. In Section 4 we tabulate the responses from the panel members to our feedback questionnaire and discuss the implications of changes introduced by them. We conclude that the net difference in seismic hazard values from those presented in Volume 4 is small and does not warrant a reanalysis. (author)

An Investigation of Short-Term Longitudinal Associations Between Social Anxiety and Victimization and Perpetration of Traditional Bullying and Cyberbullying.

Science.gov (United States)

Pabian, Sara; Vandebosch, Heidi

2016-02-01

Previous research has suggested that social anxiety is associated with victimization and perpetration of (cyber)bullying. The direction and causality of this relationship has not yet been empirically supported for both traditional and cyberbullying involvement. This study examined short-term longitudinal associations between feelings of social anxiety and involvement in traditional bullying and cyberbullying among 2128 adolescents aged 10-17 (56.6 % girls). A cross-lagged panel analysis provided evidence for the contribution of social anxiety to later victimization of bullying, both on- and off-line. The possibility of a reciprocal relationship was also examined, although it was not supported. Furthermore, longitudinal bidirectional relationships between social anxiety and the perpetration of bullying were investigated. Only one significant longitudinal association was found: the perpetration of traditional bullying predicted subsequent higher levels of social anxiety. The implications of these findings are discussed.

Social Capital, Self-Esteem, and Use of Online Social Network Sites: A Longitudinal Analysis

Science.gov (United States)

Steinfield, Charles; Ellison, Nicole B.; Lampe, Cliff

2008-01-01

A longitudinal analysis of panel data from users of a popular online social network site, Facebook, investigated the relationship between intensity of Facebook use, measures of psychological well-being, and bridging social capital. Two surveys conducted a year apart at a large U.S. university, complemented with in-depth interviews with 18 Facebook…

Study of double wall panels for use in propeller driven aircraft

Science.gov (United States)

Atwal, M.; Bernhard, R.

1984-05-01

Propeller driven aircraft have exhibited high levels of interior noise. Most absorption materials are not effective at low frequencies where maximum noise levels occur. Two panels separated by an air gap are suggested as an alternative means of noise attenuation. This design produces an impedance mismatch where a sound wave travels backwards to the source. The higher the impedance, the higher the reflected soundwave intensity. Two aluminum panels with helium in between and two panels with one being perforated were investigated. Helium increases the transmission loss because of a greater impedance mismatch than air. The transmission loss of the unperforated panel is higher throughout the frequency range tested.

Accounting for dropout reason in longitudinal studies with nonignorable dropout.

Science.gov (United States)

Moore, Camille M; MaWhinney, Samantha; Forster, Jeri E; Carlson, Nichole E; Allshouse, Amanda; Wang, Xinshuo; Routy, Jean-Pierre; Conway, Brian; Connick, Elizabeth

2017-08-01

Dropout is a common problem in longitudinal cohort studies and clinical trials, often raising concerns of nonignorable dropout. Selection, frailty, and mixture models have been proposed to account for potentially nonignorable missingness by relating the longitudinal outcome to time of dropout. In addition, many longitudinal studies encounter multiple types of missing data or reasons for dropout, such as loss to follow-up, disease progression, treatment modifications and death. When clinically distinct dropout reasons are present, it may be preferable to control for both dropout reason and time to gain additional clinical insights. This may be especially interesting when the dropout reason and dropout times differ by the primary exposure variable. We extend a semi-parametric varying-coefficient method for nonignorable dropout to accommodate dropout reason. We apply our method to untreated HIV-infected subjects recruited to the Acute Infection and Early Disease Research Program HIV cohort and compare longitudinal CD4 + T cell count in injection drug users to nonusers with two dropout reasons: anti-retroviral treatment initiation and loss to follow-up.

Political Dimensions of College Impact on Civil-libertarianism and the Integration of Political Perspective: A Longitudinal Analysis

Science.gov (United States)

Finney, Henry C.

1974-01-01

Using longitudinal data, the extent of increased civil-libertarianism among a panel of Berkeley undergraduates is assessed, along with the position of such attitudes in the progressive integration of students' political viewpoints in a more liberal and involved direction over two years. (Author)

Essaying a Pseudo-Panel Approach: Studies on Education, Women, and Income Inequality in Thailand

Science.gov (United States)

Warunsiri, Sasiwimon

2010-01-01

This dissertation is composed of three studies on Thai labor markets using a pseudo-panel data set: The first chapter estimates the rate of return to education in Thailand, while treating the endogeneity bias common to estimates from data on individuals. Pseudo-panel data are constructed from repeated cross sections of Labor Force Surveys…

Ozone exposure and pulmonary effects in panel and human clinical studies: Considerations for design and interpretation.

Science.gov (United States)

Rohr, Annette C

2018-04-01

A wealth of literature exists regarding the pulmonary effects of ozone, a photochemical pollutant produced by the reaction of nitrogen oxide and volatile organic precursors in the presence of sunlight. This paper focuses on epidemiological panel studies and human clinical studies of ozone exposure, and discusses issues specific to this pollutant that may influence study design and interpretation as well as other, broader considerations relevant to ozone-health research. The issues are discussed using examples drawn from the wider literature. The recent panel and clinical literature is also reviewed. Health outcomes considered include lung function, symptoms, and pulmonary inflammation. Issues discussed include adversity, reversibility, adaptation, variability in ozone exposure metric used and health outcomes evaluated, co-pollutants in panel studies, influence of temperature in panel studies, and multiple comparisons. Improvements in and standardization of panel study approaches are recommended to facilitate comparisons between studies as well as meta-analyses. Additional clinical studies at or near the current National Ambient Air Quality Standard (NAAQS) of 70 ppb are recommended, as are clinical studies in sensitive subpopulations such as asthmatics. The pulmonary health impacts of ozone exposure have been well documented using both epidemiological and chamber study designs. However, there are a number of specific methodological and related issues that should be considered when interpreting the results of these studies and planning additional research, including the standardization of exposure and health metrics to facilitate comparisons among studies.

Longitudinal study on osteoarthritis and bone metabolism

Directory of Open Access Journals (Sweden)

L. Postiglione

2011-09-01

Full Text Available Objective: The relationship between Osteoarthritis (OA and Osteoporosis (OP is not well defined due to lacking in longitudinal data, mainly regarding correlations between biochemical factors and OA incidence. Aim of this paper was to investigate the predictive value for OA incidence of bone mass variations and of selected biochemical markers in healthy women participating in a population-based longitudinal study carried out in Naples (Italy. Subjects and Methods: High completion rate (85.2% and statistically adequate sample size were obtained: 139 women (45 to 79 years of age were examined and follow up visit was performed after two years (24±2 months, following the same protocol. Patients underwent medical examination, questionnaire, anthropometric measurements, blood sampling and urine collection. Bone mineral density (BMD measurement was performed by dual energy X-ray absorptiometry (DEXA at the lumbar spine (L1-L4 and femoral neck. Radiographs of dorsal and lumbar spine in lateral view were performed at basal and at 24 months visits; a team of three experts scored radiographs using Kellegren and Lawrence grading. Results: The score was calculated for two individual radiographic features (narrowing of the joint space, presence of osteophytes and as a global score. Results show a relevant percentage, 23% up, of subjects presenting both OA and OP. In the cross-sectional study the presence of osteophytosis correlates with anthropometric variables and PTH levels. In the longitudinal study results show a correlation between serum vitamin D and delta score for osteophytosis (β=0.02 p<0.05. Conclusions: Data obtained outline the importance of further studies on the pathogenetic link between OA and bone metabolism.

Panel and planar experimental shear behavior of wood panels ...

African Journals Online (AJOL)

Panel shear strength along the thickness and planar shear along the length of wood panels laminated softwood oriented OSB 10 mm thick, conditioned at different moisture contents (anhydrous medium, ambient temperature and humid medium) was measured on standardized test specimens, cut in half lengthwise panel ...

Considerations on FEM modeling in analyzing buckling and plastic collapse of a detection control; Boto panel no zakutsu sosei hokai kaiseki ni okeru FEM model ka ni kansuru kosatsu

Energy Technology Data Exchange (ETDEWEB)

Yao, T; Fujikubo, M; Yanagihara, D; Irisawa, M [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

1997-10-01

Buckling and plastic collapse of upper decks and bottom outer plates of a hull results directly in longitudinal bending collapse of the hull. Therefore, discussions were given on analysis for pressure destruction strength of a detection control panel which assumes an upper deck and a bottom outer plate. Pressure destruction behavior of the panting panel is a complex phenomenon accompanying non-linearity and geometrical non-linearity of the materials. Its whole phenomenon may be analyzed by using the finite element method (FEM) as a principle, but the analysis is not efficient. Therefore, considerations were given in relation to modeling when using the FEM. The considerations were given on a panel attached with flat steel panting members with respect to the modeling scope which considers the buckling mode according to the aspect ratio of the panel partitioned by the deflection control members. If the local buckling mode of the panel is an even number wave mode in the longitudinal direction, a triple span model is required. A modeling scope for a case of being subjected to water pressure and in-plane compression was considered on a panel attached with angle-type steel members having non-symmetric cross section. In this case, a triple bay model is more preferable to reproduce the behavior under water pressure loading. 1 ref., 6 figs.

Study of low-velocity impact response of sandwich panels with shear-thickening gel cores

Science.gov (United States)

Wang, Yunpeng; Gong, Xinglong; Xuan, Shouhu

2018-06-01

The low-velocity impact response of sandwich panels with shear-thickening gel cores was studied. The impact tests indicated that the sandwich panels with shear-thickening gel cores showed excellent properties of energy dissipation and stress distribution. In comparison to the similar sandwich panels with chloroprene rubber cores and ethylene-propylene-diene monomer cores, the shear-thickening gel cores led to the obviously smaller contact forces and the larger energy absorptions. Numerical modelling with finite element analysis was used to investigate the stress distribution of the sandwich panels with shear-thickening gel cores and the results agreed well with the experimental results. Because of the unique mechanical property of the shear-thickening gel, the concentrated stress on the front facesheets were distributed to larger areas on the back facesheets and the peak stresses were reduced greatly.

75 FR 7469 - Panel Member List for Hydropower Licensing Study Dispute Resolution; Notice Extending Filing Date...

Science.gov (United States)

2010-02-19

... List for Hydropower Licensing Study Dispute Resolution; Notice Extending Filing Date for Applications for Panel Member List for Hydropower Licensing Study Dispute Resolution February 4, 2010. On October... on a list of resource experts willing to serve as a third panel member in the Commission's hydropower...

Optimum design of composite panel with photovoltaic-thermo module. Absorbing effect of cooling panel; Hikari netsu fukugo panel no saiteki sekkei. Reikyaku panel no kyunetsu koka

Energy Technology Data Exchange (ETDEWEB)

Sato, M; Kikuchi, S; Tani, T [Science University of Tokyo, Tokyo (Japan); Kadotani, K; Imaizumi, H [Komatsu Ltd., Tokyo (Japan)

1996-10-27

The composite panel with photovoltaic-thermo module becomes higher in energy-saving than the conventional air-conditioning system by the independent radiational heating and cooling effect obtained when the generating panel using a solar cell module is combined with the heating and cooling panel using a thermo-element module. The output of a solar cell module can be directly used because the solar cell module operates in AC. This paper reports the relation between the absorbed value and power consumption of the cooling panel, while paying attention to the cooling panel. The performance coefficient of the maximum absorbed value from an non-absorbing substance to a cooling panel is 2 to 3. Assume that the cooling panel during non-adiabatic operation is operated using a solar cell module of 800 W/m{sup 2} in solar intensity and 15% in conversion efficiency. The cooling-surface temperature difference is 12.12 K, and the maximum absorbed value of a non-absorbing substance to a cooling panel is 39.12 W/m{sup 2}. The absorbed value of the outer temperature to the cooling panel is 74.4 W/m{sup 2}, and each performance coefficient is 3.26 and 0.62. The absorbed value must be calculated for evaluation from the cooling-surface temperature difference measured directly from the cooling panel. 4 refs., 8 figs., 1 tab.

Authoritative parenting and religious transmission in the Netherlands: a panel study

NARCIS (Netherlands)

Vermeer, P.A.D.M.; Janssen, J.A.P.J.; Scheepers, P.L.H.

2011-01-01

This study was designed to explore the effect of authoritative parenting, over and above the effect of explicitly religious parenting practices, on the juvenile and adult church attendance of offspring. Data were collected as part of a panel study in which 474 Dutch respondents were questioned in

Experimental Research upon the Quality of the Sanded Surfaces of Some Decorative Composite Panels

Directory of Open Access Journals (Sweden)

Luminita-Maria BRENCI

2011-06-01

Full Text Available The paper presents an experimental study uponthe quantitative assessment of the surface qualityafter sanding, in case of some lignocellulosecomposite panels with decorative structure, made oflamellas obtained from different wood species,randomly jointed and having as special characteristicthe surfaces with transversal structure. The analyzedpanels were built-up in two variants: poplar withspruce wood and cherry with walnut wood. Theconstituted lamellas were finger-jointed in length andedge-jointed in width. The sanding operation wasperformed using grit sizes of 50, 80, 120 and 150. Inorder to measure the roughness parameters Ra, Rz,Rk, Rpk and Rvk, a MicroProfFRT equipment (withlight beam was used. The results revealed that thevalues of the roughness parameters had a generaldecreasing tendency with grit size increasing. Theresulted values lead to the conclusion that the finalsanding grinding system applied on longitudinalsection of wood is not valid for the transversalsection of wood which is present on the surfaces ofthe studied panels. In this special case, whensurfaces have a transversal structure, an additionalsanding with a higher grit size is needed, in order toobtain a similar roughness value as for the surfaceswith longitudinal structure.

Real scale experimental study for performance evaluation of unidirectional air diffuser perforated panels

Science.gov (United States)

Tăcutu, Laurenţiu; Nastase, Ilinca; Iordache, Vlad; Catalina, Tiberiu; Croitoru, Cristiana Verona

2018-02-01

Nowadays, there is an increasing emphasis on indoor air quality due to technological evolution and the fact that people spend most of the time in enclosed spaces. Also, energy efficiency is another related factor that gains more and more attention. Improving air distribution in an enclosure can lead to achieve these goals. This improvement can be done by adjustingthe air terminals position, theredimensions or the air diffuser perforations. The paper presents the study of 8 types of panels with different perforations shapes. The systems were characterized by flow, pressure loss and noise. Usualand special geometries were chosen, all having the same flowsurface. The perforated panels were mounted in a unidirectional air flow (UAF)diffuser, also called a laminar air flow (LAF)diffuser, that is placed in a real scale operating room (OR) in our laboratory.The purpose of this study is to determine whether changing the shape in the perforated panels can improve the technical parameters of the diffuser.

The ONS Longitudinal Study--a prestigious past and a bright future.

Science.gov (United States)

Goldring, Shayla; Newman, Jim

2010-01-01

This issue of Population Trends includes a number of articles and reports resulting from research based on the ONS Longitudinal Study (ONS LS). They have been drawn together in one issue to highlight the value of this type of study for demographic research.2009 marked the 35th anniversary of the establishment of the ONS LS. The study now contains data from the last four censuses (1971 to 2001), linked to vital events data since 1971, for a sample of one per cent of the population of England and Wales.More recently, sister studies have been established in Scotland and Northern Ireland. The Scottish Longitudinal Study (SLS) started with 1991 Census data and the Northern Ireland Longitudinal Study (NILS)started with 2001 Census data.The lead article in this issue comes from an exemplar project that was established to explore how to utilise the three studies to carry out UK-wide longitudinal analysis. Two different methods were used to analyse socio-economic and country level differences in health and mortality across the studies. The article summarises the results of this analysis, reports on the relative strengths of the different methods used, and draws attention to a number of new resources that have been developed by the project researchers as aids to using all three studies.This is an excellent example of collaborative working across the UK, involving researchers from the Centre for Longitudinal Study Information and User Support (CeLSIUS) at the London School of Hygiene and Tropical Medicine, the Longitudinal Studies Centre - Scotland (LSCS) at the University of St.Andrews and the Northern Ireland Longitudinal Study - Research Support Unit (NILS-RSU) at Queen's University Belfast. The project also involved collaboration between ONS, the General Register Office for Scotland (GROS) and the Northern Ireland Statistics and Research Agency (NISRA) to ensure the secure transfer and handling of data from the three studies so that it could be brought together in one

Longitudinal variability of time-location/activity patterns of population at different ages: a longitudinal study in California

Directory of Open Access Journals (Sweden)

Cassady Diana L

2011-09-01

Full Text Available Abstract Background Longitudinal time-activity data are important for exposure modeling, since the extent to which short-term time-activity data represent long-term activity patterns is not well understood. This study was designed to evaluate longitudinal variations in human time-activity patterns. Method We report on 24-hour recall diaries and questionnaires collected via the internet from 151 parents of young children (mostly under age 55, and from 55 older adults of ages 55 and older, for both a weekday and a weekend day every three months over an 18-month period. Parents also provided data for their children. The self-administrated diary and questionnaire distinguished ~30 frequently visited microenvironments and ~20 activities which we selected to represent opportunities for exposure to toxic environmental compounds. Due to the non-normal distribution of time-location/activity data, we employed generalized linear mixed-distribution mixed-effect models to examine intra- and inter-individual variations. Here we describe variation in the likelihood of and time spent engaging in an activity or being in a microenvironment by age group, day-type (weekday/weekend, season (warm/cool, sex, employment status, and over the follow-up period. Results As expected, day-type and season influence time spent in many location and activity categories. Longitudinal changes were also observed, e.g., young children slept less with increasing follow-up, transit time increased, and time spent on working and shopping decreased during the study, possibly related to human physiological changes with age and changes in macro-economic factors such as gas prices and the economic recession. Conclusions This study provides valuable new information about time-activity assessed longitudinally in three major age groups and greatly expands our knowledge about intra- and inter-individual variations in time-location/activity patterns. Longitudinal variations beyond weekly and

The Czech longitudinal study of optimal development

Czech Academy of Sciences Publication Activity Database

Kebza, V.; Šolcová, Iva; Kodl, M.; Kernová, V.

2012-01-01

Roč. 47, Suppl. 1 (2012), s. 266-266 ISSN 0020-7594. [International Congress of Psychology /30./. 22.07.2012-27.07.2012, Cape Town] R&D Projects: GA ČR GAP407/10/2410 Institutional support: RVO:68081740 Keywords : optimal development * Prague longitudinal study Subject RIV: AN - Psychology

Longitudinal study of fingerprint recognition.

Science.gov (United States)

Yoon, Soweon; Jain, Anil K

2015-07-14

Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject's age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis.

Public policy influence on renewable energy investments—A panel data study across OECD countries

International Nuclear Information System (INIS)

Polzin, Friedemann; Migendt, Michael; Täube, Florian A.; Flotow, Paschen von

2015-01-01

This paper examines the impact of public policy measures on renewable energy (RE) investments in electricity-generating capacity made by institutional investors. Using a novel combination of datasets and a longitudinal research design, we investigate the influence of different policy measures in a sample of OECD countries to suggest an effective policy mix which could tackle failures in the market for clean energy. The results call for technology-specific policies which take into account actual market conditions and technology maturity. To improve the conditions for institutional investments, advisable policy instruments include economic and fiscal incentives such as feed-in tariffs (FIT), especially for less mature technologies. Additionally, market-based instruments such as greenhouse gas (GHG) emission trading systems for mature technologies should be included. These policy measures directly impact the risk and return structure of RE projects. Supplementing these with regulatory measures such as codes and standards (e.g. RPS) and long-term strategic planning could further strengthen the context for RE investments. - Highlights: • Panel data study on the effectiveness of policies to induce RE investments. • Novel combination of datasets (BNEF/IEA) in solar, wind and biomass sectors. • FIT proves to be more effective than subsidies for less mature technologies. • RPS and tradable permit systems seem more effective for mature technologies. • A long-term strategic planning framework is useful to attract institutional investors

Comparing Longitudinal Profile Patterns of Mathematics and Reading in Early Child Longitudinal Study, Kindergarten: The Profile Analysis via Multidimensional Scaling (PAMS) Approach

Science.gov (United States)

Kim, Se-Kang

2010-01-01

The aim of the study is to compare longitudinal patterns from Mathematics and Reading data from the direct child assessment of Early Child Longitudinal Study, Kindergarten (ECLS-K, US Department of Education, National Center for Education Statistics 2006), utilizing Profile Analysis via Multidimensional Scaling (PAMS). PAMS has been used initially…

Photovoltaic Thermal panels in collective thermal solar systems

International Nuclear Information System (INIS)

Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.; De Lange, E.T.N.; Smit, W.F.

2003-12-01

A feasibility study has been carried out to assess the options to apply photovoltaic/thermal panels (PVT-panels) in collective solar thermal systems in urban areas in the Netherlands. The study was focused on the technical (architecture and installations) and the economical feasibility of collective PVT-systems in comparison with conventional solar thermal systems and combinations of photovoltaic (PV) panels and solar collectors. The results of the study also give insight into cost and the market for PVT-panels. Three case studies in which collective solar collector systems were applied are analyzed again by simulating the installation of a PVT-panels system and a separate solar thermal PV system [nl

Parameter study on infilled steel frames with discretely connected precast concrete panels

NARCIS (Netherlands)

Teeuwen, P.A.; Kleinman, C.S.; Snijder, H.H.; Hofmeyer, H.; Chan, S.L.

2009-01-01

This paper presents a parameter study on infilled steel frames with discretely connected precast concrete infill panels having window openings. In this study, finite element simulations were carried out to study the infilled frame performance by varying several parameters. A recently developed

JERAMI SEBAGAI BAHAN BAKU PANEL AKUSTIK PELAPIS DINDING

Directory of Open Access Journals (Sweden)

Christina E. Mediastika

2008-01-01

Full Text Available The demand of walling panels with acoustic qualification has surprisingly increased, due to the needs for home theaters and mini recording studios in the increase of environmental noise. Therefore, good supply of acoustic panels, especially those with lower price are necessary. A series of study to explore possibility in using paddy-straw as main material to construct cheap and high quality panels has been developed. Prior to this study, an earlier small research showed there was a great potency in using paddy-straw as panels, especially ones drawn from paddy in type IR. The earlier study recommends further research to examine strength of compression and tensile of the constructed panels to go for building materials, which is presented in this paper. Acoustic qualification of the panels is subject for further reserach. Abstract in Bahasa Indonesia: Kebutuhan akan panel pelapis dinding yang bersifat akustik terus meningkat seiring meningkatnya kebisingan dan kebutuhan terhadap ruang studio pribadi. Ketersediaan panel pelapis dinding dengan harga yang lebih terjangkau seperti yang terbuat dari bahan limbah sangatlah dibutuhkan. Pada penelitian awal telah diselidiki kemungkinan penggunaan jerami yang merupakan limbah sebagai bahan baku pembuatan panel akustik. Penelitian tersebut menunjukkan bahwa jerami sangat potensial digunakan sebagai bahan aku panel, terutama jerami padi berjenis IR. Selanjutnya panel jerami ini perlu mendapatkan perlakukan uji desak dan lentur untuk memastikan kemampuannya menahan berat sendiri dan kekuatannya saat proses penggunaan, sebelum akhirnya mengalami pengujian berkaitan dengan kualitas akustik. Kekuatan desak dan lentur panel dimaksud, tersaji dalam tulisan ini. Kata kunci: panel jerami, uji desak, uji lentur.

NANO-BATTERY TECHNOLOGY FOR EV-HEV PANEL: A PIONEERING STUDY

Directory of Open Access Journals (Sweden)

Ataur Rahman

2015-11-01

Full Text Available Global trends toward CO2 reduction and resource efficiency have significantly increased the importance of lightweight materials for automobile original equipment manufacturers (OEM. CO2 reduction is a fundamental driver for a more lightweight automobile. The introduction of Electrical Vehicles (EVs is one initiative towards this end. However EVs are currently facing several weaknesses: limited driving range, battery pack heaviness, lack of safety and thermal control, high cost, and overall limited efficiency. This study presents a panel-style nano-battery technology built into an EV with CuO filler solid polymer electrolyte (SPE sandwiched by carbon fiber (CF and lithium (Li plate. In addition to this, an aluminum laminated polypropylene film is used as the electromagnetic compatibility (EMC shield. The proposed battery body panel of the EV would reduce the car weight by about 20%, with a charge and discharge capacity of 1.5 kWh (10% of car total power requirement, and provide the heat insulation for the car which would save about 10% power consumption of the air conditioning system. Therefore, the EV would be benefited by 30% in terms of energy reduction by using the proposed body. Furthermore, the proposed body is considered environmental-friendly since it is recyclable for use in a new product. However, the main limiting factors of the SPE are its thermal behavior and moderate ionic conductivity at low temperatures. The SPE temperature is maintained by controlling the battery panel charging/discharge rate. It is expected that the proposed panel-style nano-battery use in an EV would save up to 6.00 kWh in battery energy, equivalent to 2.81 liters of petrol and prevent 3.081 kg of CO2 emission for a travel distance of 100 km. KEYWORDS: epoxy resin; carbon fiber; lithium thin plate; energy generation; solid electrolyte battery

Persistent work-life conflict and health satisfaction - a representative longitudinal study in Switzerland.

Science.gov (United States)

Knecht, Michaela K; Bauer, Georg F; Gutzwiller, Felix; Hämmig, Oliver

2011-04-29

The objectives of the present study were (1) to track work-life conflict in Switzerland during the years 2002 to 2008 and (2) to analyse the relationship between work-life conflict and health satisfaction, examining whether long-term work-life conflict leads to poor health satisfaction. The study is based on a representative longitudinal database (Swiss Household Panel), covering a six-year period containing seven waves of data collection. The sample includes 1261 persons, with 636 men and 625 women. Data was analysed by multi-level mixed models and analysis of variance with repeated measures. In the overall sample, there was no linear increase or decrease of work-life conflict detected, in either its time-based or strain-based form. People with higher education were more often found to have a strong work-life conflict (time- and strain-based), and more men demonstrated a strong time-based work-life conflict than women (12.2% vs. 5%). A negative relationship between work-life conflict and health satisfaction over time was found. People reporting strong work-life conflict at every wave reported lower health satisfaction than people with consistently weak work-life conflict. However, the health satisfaction of those with a continuously strong work-life conflict did not decrease during the study period. Both time-based and strain-based work-life conflict are strongly correlated to health satisfaction. However, no evidence was found for a persistent work-life conflict leading to poor health satisfaction.

A longitudinal study of tooth erosion in adolescents.

NARCIS (Netherlands)

El Aidi, H.; Bronkhorst, E.M.; Truin, G.J.

2008-01-01

Incidence studies on tooth erosion among adolescents are scarce. This longitudinal study aimed at estimating the prevalence, incidence, progression, and distribution of erosion in young adolescents over a 1.5-year period. Erosion at baseline was present in 32.2% of the 622 children (mean age, 11.9

Study of behaviour of workings in longwall panel based on field instrumentation

Energy Technology Data Exchange (ETDEWEB)

V.R. Sastry; Roshan Nair [National Institute of Technology Karnataka, Mangalore (India). Department of Mining Engineering

2009-07-01

The paper presents field monitoring study of two adjacent longwall panels based on stress measurements in longwall block and barrier, load transferred on to the gate roads and convergence measurements in the gate roads during face retreat in the panels. Results indicated that the section of barrier lying in the goaf experienced higher abutment stress when compared with the section lying ahead of face. There was a transfer of load in gate roads ahead of face after the occurrence of roof fall in goaf. Maximum cumulative convergence of more than 8 mm was observed in the gate roads during weightings.

Stressed skin panels

Energy Technology Data Exchange (ETDEWEB)

Anon

2001-07-01

Advantages and disadvantages of stressed skin panels, also known as structural insulated panels (SIPs), are discussed as material and labour-saving alternatives to traditional stick framing. Stressed skin panels are manufactured 'sandwich' assemblies with a rigid insulating polystyrene foam core, whose interior and exterior surfaces are bonded into panels. The skins distribute and carry the structural loading while the bonded foam core provides insulation and keeps the two skins aligned. Since there are fewer framing members, there is little thermal bridging and the R-value remains high. SIPs are usually manufactured in four feet by eight feet panels, although some manufacturers can produce panels up to eight feet by forty feet. SIPs are resource efficient as they use less wood than conventional framing (about 25 per cent less); can structurally cover large spans, requiring less supplementary framing. Use of SIPs eliminate the need for headers over small openings; provide the ability to nail anywhere; create less scrap and waste; lessen vulnerability to unfavourable weather and other job-site hazards, can reduce delays, and often can produce significant savings in material and labour costs. Limitations include the more complex approaches to plumbing and electrical systems, although this can be minimized by designers by incorporating much of the plumbing and electrical work on interior (non-panel) walls. Most stressed skin panels require one-half inch interior gypsum drywall. If become wet, stressed skin panels take a long time to dry out and may harbour mold growth. Larger stressed-skin panels used in floors and roofs, may require cranes or other machinery for handling because of their weight. Although not without some environmental impact, overall, stressed skin panels are judged to be a resource-efficient building technology with significant energy-efficiency benefits and distinct advantages over stick framing. 3 photos.

Computational and experimental studies of microvascular void features for passive-adaptation of structural panel dynamic properties

Science.gov (United States)

Sears, Nicholas C.; Harne, Ryan L.

2018-01-01

The performance, integrity, and safety of built-up structural systems are critical to their effective employment in diverse engineering applications. In conflict with these goals, harmonic or random excitations of structural panels may promote large amplitude oscillations that are particularly harmful when excitation energies are concentrated around natural frequencies. This contributes to fatigue concerns, performance degradation, and failure. While studies have considered active or passive damping treatments that adapt material characteristics and configurations for structural control, it remains to be understood how vibration properties of structural panels may be tailored via internal material transitions. Motivated to fill this knowledge gap, this research explores an idea of adapting the static and dynamic material distribution of panels through embedded microvascular channels and strategically placed voids that permit the internal movement of fluids within the panels for structural dynamic control. Finite element model and experimental investigations probe how redistributing material in the form of microscale voids influences the global vibration modes and natural frequencies of structural panels. Through parameter studies, the relationships among void shape, number, size, and location are quantified towards their contribution to the changing structural dynamics. For the panel composition and boundary conditions considered in this report, the findings reveal that transferring material between strategically placed voids may result in eigenfrequency changes as great as 10.0, 5.0, and 7.4% for the first, second, and third modes, respectively.

KUALITAS AKUSTIK PANEL DINDING BERBAHAN BAKU JERAMI

Directory of Open Access Journals (Sweden)

Christina E. Mediastika

2008-01-01

Full Text Available A series of study to explore possibility in using paddy-straw as main material to construct cheap and high quality panels has been developed. Prior to this study, laboratory research to examine strength of compression and tensile of the panels have been conducted, which is showed a significant value for a non-structural panel. The compression is 15 N/mm2 and tensile averaged at 0,5 N/mm2 . In this study, acoustic properties of the panels is to be examined, i.e.: transmission loss (TL, absorption coefficient (, and reverberation time (RT60. The test showed TL of 10 dB and 16 dB,  of 0,4 and 0,8 and improve RT60 from 0,88 sec to 0,35 sec and 0,16 sec (500 Hz is used for reference. Abstract in Bahasa Indonesia: Ketersediaan panel pelapis dinding yang bersifat akustik dengan harga yang lebih terjangkau seperti yang terbuat dari bahan limbah sangatlah penting. Pada penelitian awal telah diselidiki penggunaan jerami sebagai bahan baku pembuatan panel akustik, sekaligus telah dilakukan pengujian terhadap kareakteristik struktural (uji desak dan lentur dari panel tersebut. Dari uji kekuatan struktural, panel memiliki kekuatan desak mencapai 15 N/mm2 dan kuat lentur reta-rata 0,5 N/mm2. Kekuatan ini dianggap mencukupi bagi panel non-struktural yang hanya bertugas untuk memikul beban sendiri. Oleh karena tujuan awal pembuatan panel adalah untuk kepentingan akustik, maka pada penelitian lanjutan, dilakukan uji laboratorium dan lapangan untuk melihat karakterisktik akustiknya. Adapun pengujian meliputi: redaman/insulasi (TL, koefisien serap ( dan waktu dengung (RT60. Dari hasil pengujian, panel mempunyai TL 10 dB dan 16 dB,  0,4 dan 0,8, serta mampu memperbaiki RT60 ruangan dari 0,88 detik menjadi 0,35 detik dan 0,16 detik. Kesemua pengujian menggunakan band frekuensi 500 Hz sebagai acuan. Kata kunci: panel jerami, insulasi, koefisien serap, waktu dengung.

Nutritional status and quality of life of cancer patients needing exclusive chemotherapy: a longitudinal study.

Science.gov (United States)

Salas, Sebastien; Mercier, Sophie; Moheng, Benjamin; Olivet, Sandrine; Garcia, Marie-Eve; Hamon, Sophie; Sibertin-Blanc, Camille; Duffaud, Florence; Auquier, Pascal; Baumstarck, Karine

2017-04-27

The aims of this study were to report nutritional status in a large panel of patients with cancer requiring exclusive chemotherapy and to study the influence of nutritional status on their quality of life (QoL). This work was a longitudinal cohort study performed at a French university teaching hospital. Eligible patients were individuals with a cancer needing treatment based on exclusive chemotherapy. Three work-ups were performed: i) before the administration of the first course of chemotherapy: T1, ii) before the administration of the second (for patients with 3 planned courses) or third (patients with 6 planned courses) course: T2, and iii) before the administration of the last planned course: T3. The following data were collected: general health (performance status) and nutritional status (weight, anorexia grading, albuminemia, pre-albuminemia, and C-reactive protein) and QoL. The nutritional status of patients with cancer was preserved. Functional impairment, the presence of anorexia, the palliative nature of the chemotherapy, and an elevated C-reactive protein dosage were independent predictive factors of a lower QoL among patients assessed at the end of chemotherapy. Although larger studies should corroborate these findings, clinicians may include this information in the management of patients with cancer requiring exclusive chemotherapy to identify the most vulnerable patients. Current controlled trials NCT01687335 (registration date: October 6, 2011).

Comprehensive metabolic panel

Science.gov (United States)

Metabolic panel - comprehensive; Chem-20; SMA20; Sequential multi-channel analysis with computer-20; SMAC20; Metabolic panel 20 ... Chernecky CC, Berger BJ. Comprehensive metabolic panel (CMP) - blood. In: ... Tests and Diagnostic Procedures . 6th ed. St Louis, MO: ...

A Longitudinal Study of School Districts' Sustained Improvement

Science.gov (United States)

Sampson, Pauline M.

2011-01-01

In this longitudinal study of one region in the state of Texas, there was an examination of district leadership and the sustaining of high student achievement for their districts. The results of this study suggest that sustained improvement of student achievement is very difficult. The districts that had sustained improvement had stable district…

Noise Reduction in Double‿Panel Structures by Cavity and Panel Resonance Control

NARCIS (Netherlands)

Ho, J.; Berkhoff, Arthur P.

2011-01-01

This paper presents an investigation of the cavity and the panel resonance control in a double‿panel structure. The double‿panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its light weight and effective

Noise reduction in double-panel structures by cavity and panel resonance control

NARCIS (Netherlands)

Ho, J.-H.; Berkhoff, A.P

2011-01-01

This paper presents an investigation of the cavity and the panel resonance control in a double‐panel structure. The double‐panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its light weight and effective

A study on development of virtual panel and virtual collaboration system

International Nuclear Information System (INIS)

Yoo, H. J.; Park, S. Y.; Lee, M. S.; Hong, J. H.

2001-01-01

The Nuclear I and C group of KEPRI has been peforming research and development on the VRCATS, Virtual Reality based Computer Assisted Training System. For the past two years, we have developed the first VRCATS for Youngkwang 1 nuclear power plant. Currently, we are developing an advanced VRCATS for Uljin 3 nuclear power plant. In this paepr, we will describe virtual panel system and VR based collaborate training system (VRCATS) of the Uljin VRCATS. Since Virtual Panel provides the same environment as the real MCR, trainees can expect the same training effect with Virtual Panel as they do with full scope simulator. i.e., trainees can check key variables and operate the plants and get responses with Virtual Panel. VRCTS provides another realistic training environment for trainees. In VRCATS, for example, operators in a group can work together t handle LOCA (Loss of Coolant Accident) according to emergency operation procedures

Performance Evaluation of PV Panel Under Dusty Condition

Directory of Open Access Journals (Sweden)

Abhishek Kumar Tripathi

2017-11-01

Full Text Available The performance of PV panel depends on the incoming sunlight on its surface. The accumulated airborne dust particles on panel surface creates a barrier in the path of sunlight and panel surface, which significantly reduces the amount of solar radiation falling on the panel surface. The present study shows a significant reduction in short circuit current and power output of PV panel due to dust deposition on its surface, whereas the reduction in open circuit voltage is not much prominent. This study has been carried in the field as well as in the laboratory. The reduction in maximum power output of PV panel for both the studies ensures a linear relation with the dust deposition on its surface. In the field study, the reduction in the power output due to 12.86gm of dust deposition on the panel surface was 43.18%, whereas in the laboratory study it was 44.75% due to 11gm of dust deposition Article History: Received July 10th 2017; Received in revised form Sept 15th 2017x; Accepted 1st Oct 2017; Available online How to Cite This Article: Tripathi, A.K., Aruna, M. and Murthy, Ch.,S.N. (2017. Performance Evaluation of PV Panel Under Dusty Condition. International Journal of Renewable Energy Develeopment, 6(3, 225-233. https://doi.org/10.14710/ijred.6.3.225-233

PERBANDINGAN UNJUK KERJA ANTARA PANEL SEL SURYA BERPENJEJAK DENGAN PANEL SEL SURYA DIAM

Directory of Open Access Journals (Sweden)

Syafaruddin Ch

2010-07-01

Full Text Available The ability to produce electrical energy at Solar Power Plant  is highly dependent on the magnitude and duration of sun exposure on the solar cell panels. The movement of the sun from east to west that periodicity in every day is a problem at  the  optimization generation of electricity at  Solar Power Plant   if using solar panel that motionless. This is because the solar cell panel can not catch the maximum sun exposure. To solve the above problem then designed a solar cell panel  tracker  capable of follo-wing the movements of the sun. Then conducted a test to see the performance of solar cell pa-nel  tracker  and compare it with the performance of solar cell panel was motionless. The testing doing along 6 days, with way to irradiate the panel of solar cells  tracker  and panels of solar cell motionless with sun exposure  along a  full day. Then the electric current generated each panel were recorded. The comparison of current then generating comparison of electric power delivery. The result show that the solar cell panel  tracker  produce the average current is 2.19 A whereas solar-cell panel still 1.97 A.  This result   indicate that average power for solar cell panel  tracker  39.41 W while for solar cell panel that motionless is  35.46 W. These results indicate that the performance of solar cell panel  tracker  better than  solar cell panel motionless.

Noise Reduction in Double‿Panel Structures by Cavity and Panel Resonance Control

OpenAIRE

Ho, J.; Berkhoff, Arthur P.

2011-01-01

This paper presents an investigation of the cavity and the panel resonance control in a double‿panel structure. The double‿panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its light weight and effective transmission‿loss at high frequency. However, the resonance of the cavity and the poor transmission‿loss at low frequency limit its noise control performance. Applying active control forces on the panels or utili...

Panel cutting method: new approach to generate panels on a hull in Rankine source potential approximation

Directory of Open Access Journals (Sweden)

Hee-Jong Choi

2011-12-01

Full Text Available In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 (CB=0.60 hull and KRISO container ship (KCS, a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI. The computational results were validated by comparing with the existing experimental data.

Panel cutting method: new approach to generate panels on a hull in Rankine source potential approximation

Science.gov (United States)

Choi, Hee-Jong; Chun, Ho-Hwan; Park, Il-Ryong; Kim, Jin

2011-12-01

In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 (CB=0.60) hull and KRISO container ship (KCS), a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI). The computational results were validated by comparing with the existing experimental data.

The TVT Glass Pavilion: Theoretical Study on a Highly Transparent Building Made with Long-Spanned TVT Portals Braced with Hybrid Glass-Steel Panels

Directory of Open Access Journals (Sweden)

Maurizio Froli

2017-06-01

Full Text Available In contemporary buildings, the architectural demand for a complete dematerialisation of load bearing structures can be satisfied only in limited cases with the exclusive structural use of glass. Otherwise, for challenging applications such as long spanned or high-rise structures, the use of hybrid glass-steel systems is mandatory. Glass, fragile but highly compressive resistant, is associated with steel, ductile and tensile resistant. The present research shows the feasibility study for a fully glazed pavilion made of six TVT (Travi Vitree Tensegrity portal frames longitudinally braced by pre-stressed hybrid glass panels. The frames are about 20 m in span and 8 m in height. Appropriate multiscalar FEM numerical analyses, calibrated on the collapse tests performed on previous TVT large-scale prototypes, stated that the structural performance would be able to withstand heavy static and dynamic loads and stated the observance of the Fail-Safe Design principles.

Simulation study of air and water cooled photovoltaic panel using ANSYS

Science.gov (United States)

Syafiqah, Z.; Amin, N. A. M.; Irwan, Y. M.; Majid, M. S. A.; Aziz, N. A.

2017-10-01

Demand for alternative energy is growing due to decrease of fossil fuels sources. One of the promising and popular renewable energy technology is a photovoltaic (PV) technology. During the actual operation of PV cells, only around 15% of solar irradiance is converted to electricity, while the rest is converted into heat. The electrical efficiency decreases with the increment in PV panel’s temperature. This electrical energy is referring to the open-circuit voltage (Voc), short-circuit current (Isc) and output power generate. This paper examines and discusses the PV panel with water and air cooling system. The air cooling system was installed at the back of PV panel while water cooling system at front surface. The analyses of both cooling systems were done by using ANSYS CFX and PSPICE software. The highest temperature of PV panel without cooling system is 66.3 °C. There is a decrement of 19.2% and 53.2% in temperature with the air and water cooling system applied to PV panel.

Longitudinal Andhra Pradesh Eye Disease Study: rationale, study design and research methodology.

Science.gov (United States)

Khanna, Rohit C; Murthy, Gudlavalleti Vs; Marmamula, Srinivas; Mettla, Asha Latha; Giridhar, Pyda; Banerjee, Seema; Shekhar, Konegari; Chakrabarti, Subhabrata; Gilbert, Clare; Rao, Gullapalli N

2016-03-01

The rationale, objectives, study design and procedures for the longitudinal Andhra Pradesh Eye Disease Study are described. A longitudinal cohort study was carried out. Participants include surviving cohort from the rural component of Andhra Pradesh Eye Disease Study. During 1996-2000, Andhra Pradesh Eye Disease Survey was conducted in three rural (n = 7771) and one urban (n = 2522) areas (now called Andhra Pradesh Eye Disease Study 1). In 2009-2010, a feasibility exercise (Andhra Pradesh Eye Disease Study 2) for a longitudinal study (Andhra Pradesh Eye Disease Study 3) was undertaken in the rural clusters only, as urban clusters no longer existed. In Andhra Pradesh Eye Disease Study 3, a detailed interview will be carried out to collect data on sociodemographic factors, ocular and systemic history, risk factors, visual function, knowledge of eye diseases and barriers to accessing services. All participants will also undergo a comprehensive eye examination including photography of lens, optic disc and retina, Optic Coherence Tomography of the posterior segment, anthropometry, blood pressure and frailty measures. Measures include estimates of the incidence of visual impairment and age-related eye disease (lens opacities, glaucoma and age-related macular degeneration) and the progression of eye disease (lens opacities and myopia) and associated risk factors. Of the 7771 respondents examined in rural areas in Andhra Pradesh Eye Disease Study 1, 5447 (70.1%) participants were traced in Andhra Pradesh Eye Disease Study 2. These participants will be re-examined. Andhra Pradesh Eye Disease Study 3 will provide data on the incidence and progression of visual impairment and major eye diseases and their associated risk factors in India. The study will provide further evidence to aid planning eye care services. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

Unemployment and psychological distress among graduates: A longitudinal study

NARCIS (Netherlands)

Schaufeli, Wilmar B.; Van Yperen, Nico W.

1992-01-01

A longitudinal study which addresses the relationship between unemployment and psychological distress in Dutch technical college graduates is presented. Two samples were studied: sample 1 (N = 635) consisted of students leaving technical college and sample 2 (N = 487) consisted of technical college

Paneling architectural freeform surfaces

KAUST Repository

Eigensatz, Michael

2010-07-25

The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, so-called panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects.

Paneling architectural freeform surfaces

KAUST Repository

Eigensatz, Michael

2010-07-26

The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, socalled panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects. © 2010 ACM.

The Timing of Maternal Depressive Symptoms and Child Cognitive Development: A Longitudinal Study

Science.gov (United States)

Evans, Jonathan; Melotti, Roberto; Heron, Jon; Ramchandani, Paul; Wiles, Nicola; Murray, Lynne; Stein, Alan

2012-01-01

Background: Maternal depression is known to be associated with impairments in child cognitive development, although the effect of timing of exposure to maternal depression is unclear. Methods: Data collected for the Avon Longitudinal Study of Parents and Children, a longitudinal study beginning in pregnancy, included self-report measures of…

Performance analysis of PV panel under varying surface temperature

Directory of Open Access Journals (Sweden)

Kumar Tripathi Abhishek

2018-01-01

Full Text Available The surface temperature of PV panel has an adverse impact on its performance. The several electrical parameters of PV panel, such as open circuit voltage, short circuit current, power output and fill factor depends on the surface temperature of PV panel. In the present study, an experimental work was carried out to investigate the influence of PV panel surface temperature on its electrical parameters. The results obtained from this experimental study show a significant reduction in the performance of PV panel with an increase in panel surface temperature. A 5W PV panel experienced a 0.4% decrease in open circuit voltage for every 1°C increase in panel surface temperature. Similarly, there was 0.6% and 0.32% decrease in maximum power output and in fill factor, respectively, for every 1°C increase in panel surface temperature. On the other hand, the short circuit current increases with the increase in surface temperature at the rate of 0.09%/°C.

Proceedings: special panel on geothermal model intercomparison study

Energy Technology Data Exchange (ETDEWEB)

1980-12-17

Separate abstracts were prepared for five papers. Two papers were abstracted previously for EDB. Five panel responses to the project, three workshop session summaries, and conclusions drawn are also included in this report. (MHR)

Sustainable Absorption Panels from Agricultural Wastes

Directory of Open Access Journals (Sweden)

Ismail F.Z.

2014-01-01

Full Text Available Noise has become a serious environmental problem and there are demands for alternative sustainable materials which capable to reduce the noise level at various frequency ranges. Therefore, the aim of this research is to study the potential of turning the agricultural waste and waste paper into a sound absorption panel. For the purpose of this study, combination of two materials was under studied; coconut coir fibre from agriculture waste and shredded waste paper from the office. There were two main objective of the research; first is to develop absorption panels from coconut coir powder that available locally with a combination of shredded paper at different percentage of mixture. Second objective is to identify the absorption rate of the panels. The study encompasses the fabrication of the particle board using the coconut husk powder mix with shredded waste paper and using the gypsum powder as the binder for the two materials. Four acoustic panels of size 0.5m x 0.5m and 0.012 m thick were fabricated with different mix ratio; 25% of coconut coir powder mixed with 75% of shredded waste papers for sample 1, 50% both of the material for sample 2, 75% of coconut coir powder mixed with 25% of shredded waste paper for sample 3, and lastly 100% of coconut coir powder for sample 4. The absorption coefficient of the panels was tested in a reverberation chamber and in accordance with ISO 354:1985 standards. Based on the results, sample 1 gave the highest absorption coefficient compared to sample 2, 3 and 4. It can be concluded that the acoustic panel made from a mixture of 25% coconut coir powder with 75% shredded waste paper provided higher absorption coefficient compared to the performance of the other samples. This might be caused by the size of the coir powder which is very small, creating less void space in between the panel and thus causing it to absorb less sound. Since sound absorption is very much affected by the availability of void space of

The USA National Longitudinal Lesbian Family Study (NLLFS): homophobia, psychological adjustment, and protective factors

NARCIS (Netherlands)

Bos, H.M.W.; Gartrell, N.K.; Peyser, H.; van Balen, F.

2008-01-01

The study assessed the influence of protective factors on the psychological adjustment of children who had experienced homophobia and whose mothers were participants in a longitudinal study of planned lesbian families. Data were collected as part of the National Longitudinal Lesbian Family Study by

Comparisons between various cavity and panel noise reduction control in double-panel structures

NARCIS (Netherlands)

Ho, J.H.; Kalverboer, J.; Berkhoff, A.P.

2012-01-01

This paper presents comparisons between various panel and cavity resonance control methods to reduce the transmitted sound in a double-panel structure. The double-panel, which consists of two panels with air in the gap, has the advantages of low weight and effective transmission-loss at high

Experimental studies on multicellular GFRP bridge deck panels ...

Indian Academy of Sciences (India)

M P MUTHURAJ

2017-11-20

Nov 20, 2017 ... design of a new bridge deck panel made of GFRP. .... cient manufacturing processes with minimal wastage. But re-use of the remaining FRP elements during manufacture ... Energy consumption for production of different.

Integrated Thermal Treatment Systems study: US Department of Energy Internal Review Panel report

International Nuclear Information System (INIS)

Cudahy, J.; Escarda, T.; Gimpel, R.

1995-04-01

The U.S. Department of Energy's (DOE) Office of Technology Development (OTD) commissioned two studies to uniformly evaluate nineteen thermal treatment technologies. These studies were called the Integrated Thermal Treatment System (ITTS) Phase I and Phase II. With the advice and guidance of the DOE Office of Environmental Management's (EM's) Mixed Waste Focus Group, OTD formed an ITTS Internal Review Panel, composed of scientists and engineers from throughout the DOE complex, the U.S. Environmental Protection Agency (EPA), the California EPA, and private experts. The Panel met from November 15-18, 1994, to review and comment on the ITTS studies, to make recommendations on the most promising thermal treatment systems for DOE mixed low level wastes (MLLW), and to make recommendations on research and development necessary to prove the performance of the technologies on MLLW

Comparative study on diagonal equivalent methods of masonry infill panel

Science.gov (United States)

Amalia, Aniendhita Rizki; Iranata, Data

2017-06-01

Infrastructure construction in earthquake prone area needs good design process, including modeling a structure in a correct way to reduce damages caused by an earthquake. Earthquakes cause many damages e.g. collapsed buildings that are dangerous. An incorrect modeling in design process certainly affects the structure's ability in responding to load, i.e. an earthquake load, and it needs to be paid attention to in order to reduce damages and fatalities. A correct modeling considers every aspect that affects the strength of a building, including stiffness of resisting lateral loads caused by an earthquake. Most of structural analyses still use open frame method that does not consider the effect of stiffness of masonry panel to the stiffness and strength of the whole structure. Effect of masonry panel is usually not included in design process, but the presence of this panel greatly affects behavior of the building in responding to an earthquake. In worst case scenario, it can even cause the building to collapse as what has been reported after great earthquakes worldwide. Modeling a structure with masonry panel as consideration can be performed by designing the panel as compression brace or shell element. In designing masonry panel as a compression brace, there are fourteen methods popular to be used by structure designers formulated by Saneinejad-Hobbs, Holmes, Stafford-Smith, Mainstones, Mainstones-Weeks, Bazan-Meli, Liauw Kwan, Paulay and Priestley, FEMA 356, Durani Luo, Hendry, Al-Chaar, Papia and Chen-Iranata. Every method has its own equation and parameters to use, therefore the model of every method was compared to results of experimental test to see which one gives closer values. Moreover, those methods also need to be compared to the open frame to see if they can result values within limits. Experimental test that was used in comparing all methods was taken from Mehrabi's research (Fig. 1), which was a prototype of a frame in a structure with 0.5 scale and the

Who opts for self-employment after retirement? A longitudinal study in the Netherlands.

Science.gov (United States)

van Solinge, Hanna

2014-09-01

Self-employment among older age groups is rising. A better understanding of the role of self-employment in extending the working lives of individuals is, therefore, relevant from a policy perspective. By bridging the gap in the literature on work/retirement decision-making and entrepreneurship, the present study examines the factors associated with entry into self-employment post-retirement, after a worker has left a regular salaried position. This decision is modelled as a choice between full retirement and prolonged labour force participation, in the form of either a typical wage-providing job or self-employment. Data were derived from the Netherlands Interdisciplinary Demographic Institute Work and Retirement Panel, an ongoing longitudinal survey of older workers (50 years and over) employed by three private sector organisations and employed as civil servants in the Netherlands. These data were then analysed using multinomial logistic regression analysis. The results of this study show that the decision to pursue self-employment is primarily taken by retirees with relatively high levels of financial and human capital (wealth and educational attainment), those possessing entrepreneurial attitudes (high self-efficacy scores) and those who perceive their retirements to be completely involuntary. The results lend support to self-employment being selected as a postretirement path through opportunity rather than out of necessity. The fact that the retirements of the studied population were generally quite early, while not considered involuntary also suggests that the timing of the decision to retire may be driven by the emergence of new (business) opportunities.

Persistent work-life conflict and health satisfaction - A representative longitudinal study in Switzerland

Science.gov (United States)

2011-01-01

Background The objectives of the present study were (1) to track work-life conflict in Switzerland during the years 2002 to 2008 and (2) to analyse the relationship between work-life conflict and health satisfaction, examining whether long-term work-life conflict leads to poor health satisfaction. Methods The study is based on a representative longitudinal database (Swiss Household Panel), covering a six-year period containing seven waves of data collection. The sample includes 1261 persons, with 636 men and 625 women. Data was analysed by multi-level mixed models and analysis of variance with repeated measures. Results In the overall sample, there was no linear increase or decrease of work-life conflict detected, in either its time-based or strain-based form. People with higher education were more often found to have a strong work-life conflict (time- and strain-based), and more men demonstrated a strong time-based work-life conflict than women (12.2% vs. 5%). A negative relationship between work-life conflict and health satisfaction over time was found. People reporting strong work-life conflict at every wave reported lower health satisfaction than people with consistently weak work-life conflict. However, the health satisfaction of those with a continuously strong work-life conflict did not decrease during the study period. Conclusions Both time-based and strain-based work-life conflict are strongly correlated to health satisfaction. However, no evidence was found for a persistent work-life conflict leading to poor health satisfaction. PMID:21529345

Persistent work-life conflict and health satisfaction - A representative longitudinal study in Switzerland

Directory of Open Access Journals (Sweden)

Hämmig Oliver

2011-04-01

Full Text Available Abstract Background The objectives of the present study were (1 to track work-life conflict in Switzerland during the years 2002 to 2008 and (2 to analyse the relationship between work-life conflict and health satisfaction, examining whether long-term work-life conflict leads to poor health satisfaction. Methods The study is based on a representative longitudinal database (Swiss Household Panel, covering a six-year period containing seven waves of data collection. The sample includes 1261 persons, with 636 men and 625 women. Data was analysed by multi-level mixed models and analysis of variance with repeated measures. Results In the overall sample, there was no linear increase or decrease of work-life conflict detected, in either its time-based or strain-based form. People with higher education were more often found to have a strong work-life conflict (time- and strain-based, and more men demonstrated a strong time-based work-life conflict than women (12.2% vs. 5%. A negative relationship between work-life conflict and health satisfaction over time was found. People reporting strong work-life conflict at every wave reported lower health satisfaction than people with consistently weak work-life conflict. However, the health satisfaction of those with a continuously strong work-life conflict did not decrease during the study period. Conclusions Both time-based and strain-based work-life conflict are strongly correlated to health satisfaction. However, no evidence was found for a persistent work-life conflict leading to poor health satisfaction.

Advanced solar panel designs

Science.gov (United States)

Ralph, E. L.; Linder, E.

1995-01-01

This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

Developmental trajectories and longitudinal mediation effects of self-esteem, peer attachment, child maltreatment and depression on early adolescents.

Science.gov (United States)

Ju, Soyoung; Lee, Yanghee

2018-02-01

The purpose of this study is to identify the developmental trajectories of peer attachment, self-esteem, depression, and child maltreatment, and to understand the longitudinal mediation effects that peer attachment and self-esteem have on the influence of perceived abuse on early adolescent depression. This study uses Year 1 to Year 5 data of the 4th grader panel of the Korea Youth Panel Survey (KYPS) and utilizes a multivariate latent growth model to analyze the main variables in the applicable data between 5th (i.e., Year 2) and 8th (i.e., Year 5) grades. The results indicate that from the 5th to the 8th grade, the degree of abuse and depression increases while self-esteem gradually decreases with slowly lowering peer attachment. A significant distribution of the initial values and the rate of change were present for all main variables of the study, confirming individual differences in time wise changes. Further, more exposure to abuse correlated with a decrease in self-esteem, while an increase in self-esteem greatly reduced depression. The initial value of self-esteem showed a partial mediation effect, whereas the rate of change indicated a full mediation effect with a significant longitudinal mediation effect. More experience of abuse during early adolescence indicated a lower degree of peer attachment, and a higher peer attachment was related to decreased depression. A significant partial mediation effect was present for both the initial value and the rate of change of peer attachment, and a longitudinal mediation effect was present. This study confirmed that self-esteem in early adolescents is an important protective factor that can greatly reduce the degree of depression, and suggests continuous interventions conducted to increase self-esteem in adolescence. Furthermore, by determining that peer attachment decreases the degree of depression in children at risk, the study emphasizes the healing aspect of adolescent peer attachment. Copyright © 2017 Elsevier

[Information management in multicenter studies: the Brazilian longitudinal study for adult health].

Science.gov (United States)

Duncan, Bruce Bartholow; Vigo, Álvaro; Hernandez, Émerson; Luft, Vivian Cristine; Ahlert, Hubert; Bergmann, Kaiser; Mota, Eduardo

2013-06-01

Information management in large multicenter studies requires a specialized approach. The Estudo Longitudinal da Saúde do Adulto (ELSA-Brasil - Brazilian Longitudinal Study for Adult Health) has created a Datacenter to enter and manage its data system. The aim of this paper is to describe the steps involved, including the information entry, transmission and management methods. A web system was developed in order to allow, in a safe and confidential way, online data entry, checking and editing, as well as the incorporation of data collected on paper. Additionally, a Picture Archiving and Communication System was implemented and customized for echocardiography and retinography. It stores the images received from the Investigation Centers and makes them available at the Reading Centers. Finally, data extraction and cleaning processes were developed to create databases in formats that enable analyses in multiple statistical packages.

Applied longitudinal analysis

CERN Document Server

Fitzmaurice, Garrett M; Ware, James H

2012-01-01

Praise for the First Edition "". . . [this book] should be on the shelf of everyone interested in . . . longitudinal data analysis.""-Journal of the American Statistical Association   Features newly developed topics and applications of the analysis of longitudinal data Applied Longitudinal Analysis, Second Edition presents modern methods for analyzing data from longitudinal studies and now features the latest state-of-the-art techniques. The book emphasizes practical, rather than theoretical, aspects of methods for the analysis of diverse types of lo

Solar reflection panels

Science.gov (United States)

Diver, Jr., Richard B.; Grossman, James W [Albuquerque, NM; Reshetnik, Michael [Boulder, CO

2006-07-18

A solar collector comprising a glass mirror, and a composite panel, wherein the back of the mirror is affixed to a front surface of the composite panel. The composite panel comprises a front sheet affixed to a surface of a core material, preferably a core material comprising a honeycomb structure, and a back sheet affixed to an opposite surface of the core material. The invention may further comprise a sealing strip, preferably comprising EPDM, positioned between the glass mirror and the front surface of the composite panel. The invention also is of methods of making such solar collectors.

Numerical simulation of wind loads on solar panels

Science.gov (United States)

Su, Kao-Chun; Chung, Kung-Ming; Hsu, Shu-Tsung

2018-05-01

Solar panels mounted on the roof of a building or ground are often vulnerable to strong wind loads. This study aims to investigate wind loads on solar panels using computational fluid dynamic (CFD). The results show good agreement with wind tunnel data, e.g. the streamwise distribution of mean surface pressure coefficient of a solar panel. Wind uplift for solar panels with four aspect ratios is evaluated. The effect of inclined angle and clearance (or height) of a solar panel is addressed. It is found that wind uplift of a solar panel increases when there is an increase in inclined angle and the clearance above ground shows an opposite effect.

A longitudinal study of urea cycle disorders.

Science.gov (United States)

Batshaw, Mark L; Tuchman, Mendel; Summar, Marshall; Seminara, Jennifer

2014-01-01

The Urea Cycle Disorders Consortium (UCDC) is a member of the NIH funded Rare Diseases Clinical Research Network and is performing a longitudinal study of 8 urea cycle disorders (UCDs) with initial enrollment beginning in 2006. The consortium consists of 14 sites in the U.S., Canada and Europe. This report summarizes data mining studies of 614 patients with UCDs enrolled in the UCDC's longitudinal study protocol. The most common disorder is ornithine transcarbamylase deficiency, accounting for more than half of the participants. We calculated the overall prevalence of urea cycle disorders to be 1/35,000, with 2/3rds presenting initial symptoms after the newborn period. We found the mortality rate to be 24% in neonatal onset cases and 11% in late onset cases. The most common precipitant of clinical hyperammonemic episodes in the post-neonatal period was intercurrent infections. Elevations in both blood ammonia and glutamine appeared to be biomarkers for neurocognitive outcome. In terms of chronic treatment, low protein diet appeared to result in normal weight but decreased linear growth while N-scavenger therapy with phenylbutyrate resulted in low levels of branched chain amino acids. Finally, we found an unexpectedly high risk for hepatic dysfunction in patients with ornithine transcarbamylase deficiency. This natural history study illustrates how a collaborative study of a rare genetic disorder can result in an improved understanding of morbidity and disease outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

Proficiency testing for sensory profile panels : measuring panel performance

NARCIS (Netherlands)

Mcewan, J.A.; Hunter, E.A.; Gemert, L.J. van; Lea, P.

2002-01-01

Proficiency testing in sensory analysis is an important step towards demonstrating that results from one sensory panel are consistent with the results of other sensory panels. The uniqueness of sensory analysis poses some specific problems for measuring the proficiency of the human instrument

Use of missing data methods in longitudinal studies: the persistence of bad practices in developmental psychology.

Science.gov (United States)

Jelicić, Helena; Phelps, Erin; Lerner, Richard M

2009-07-01

Developmental science rests on describing, explaining, and optimizing intraindividual changes and, hence, empirically requires longitudinal research. Problems of missing data arise in most longitudinal studies, thus creating challenges for interpreting the substance and structure of intraindividual change. Using a sample of reports of longitudinal studies obtained from three flagship developmental journals-Child Development, Developmental Psychology, and Journal of Research on Adolescence-we examined the number of longitudinal studies reporting missing data and the missing data techniques used. Of the 100 longitudinal studies sampled, 57 either reported having missing data or had discrepancies in sample sizes reported for different analyses. The majority of these studies (82%) used missing data techniques that are statistically problematic (either listwise deletion or pairwise deletion) and not among the methods recommended by statisticians (i.e., the direct maximum likelihood method and the multiple imputation method). Implications of these results for developmental theory and application, and the need for understanding the consequences of using statistically inappropriate missing data techniques with actual longitudinal data sets, are discussed.

Vacuum Insulation Panels - Study on VIP-components and panels for service life prediction of VIP in building applications (Subtask A)

Energy Technology Data Exchange (ETDEWEB)

Simmler, H.; Brunner, S. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland); Heinemann, U.; Schwab, H. [Bavarian Centre for Applied Energy Research (ZAE Bayern), Garching (Germany); Kumaran, K.; Mukhopadhyaya, P. [National Research Council, Institute for Research in Construction (NRC-IRC), Ottawa (Canada); Quenard, D.; Sallee, H. [Scientific and Technical Centre for Construction (CSTB), Marne la Vallee (France); Noller, K.; Kuecuekpinar-Niarchos, E.; Stramm, C. [Fraunhofer Institute for Process Engineering and Packaging (IVV), Freising (Germany); Tenpierik, M.; Cauberg, H. [Technical University of Delft, Delft (Netherlands); Erb, M. [Dr. Eicher und Pauli AG (Switzerland)

2005-09-15

This comprehensive paper takes a look at the properties of vacuum insulation panels (VIP) and was presented as a contribution to the IEA's ECBCS (Energy Conservation in Buildings and Community Systems) Annex 39. The various institutions in Switzerland, Germany, Canada, France, Sweden and the Netherlands participating in the task and their activities are listed. The paper describes the concept of vacuum insulation for buildings and examines the physics involved and core materials that can be used. The physical, mechanical and thermal properties of the core materials are examined and the requirements placed on the envelope of the panels are looked at. Tests made on materials as well as on the complete vacuum insulation panels are described in detail. The results obtained are presented and reviewed. Service-life and quality assurance aspects are also discussed. A comprehensive appendix completes the report.

A panel study on the relationship between corruption and government size

OpenAIRE

Go, Kotera; Okada, Keisuke; Samreth, Sovannroeun

2010-01-01

Using panel data from 1996 to 2005, this paper shows that the effect of government size on corruption is positive at a low level of democracy, but it is negative at a high level. This finding could fill the gaps in previous studies whose findings on the relationship between corruption and government size are controversial.

A Longitudinal Study of Gender-Related Cognition and Behaviour

Science.gov (United States)

Campbell, Anne; Shirley, Louisa; Candy, Julia

2004-01-01

Gender schema theory proposes that children's acquisition of gender labels and gender stereotypes informs gender-congruent behaviour. Most previous studies have been cross-sectional and do not address the temporal relationship between knowledge and behaviour. We report the results of a longitudinal study of gender knowledge and sex-typed behaviour…

Large thermal protection system panel

Science.gov (United States)

Weinberg, David J. (Inventor); Myers, Franklin K. (Inventor); Tran, Tu T. (Inventor)

2003-01-01

A protective panel for a reusable launch vehicle provides enhanced moisture protection, simplified maintenance, and increased temperature resistance. The protective panel includes an outer ceramic matrix composite (CMC) panel, and an insulative bag assembly coupled to the outer CMC panel for isolating the launch vehicle from elevated temperatures and moisture. A standoff attachment system attaches the outer CMC panel and the bag assembly to the primary structure of the launch vehicle. The insulative bag assembly includes a foil bag having a first opening shrink fitted to the outer CMC panel such that the first opening and the outer CMC panel form a water tight seal at temperatures below a desired temperature threshold. Fibrous insulation is contained within the foil bag for protecting the launch vehicle from elevated temperatures. The insulative bag assembly further includes a back panel coupled to a second opening of the foil bag such that the fibrous insulation is encapsulated by the back panel, the foil bag, and the outer CMC panel. The use of a CMC material for the outer panel in conjunction with the insulative bag assembly eliminates the need for waterproofing processes, and ultimately allows for more efficient reentry profiles.

Reflecting variable opening insulating panel

International Nuclear Information System (INIS)

Nungesser, W.T.

1976-01-01

A description is given of a reflecting variable opening insulating panel assembly, comprising a static panel assembly of reflecting insulation sheets forming a cavity along one side of the panel and a movable panel opening out by sliding from the cavity of the static panel, and a locking device for holding the movable panel in a position extending from the cavity of the static panel. This can apply to a nuclear reactor of which the base might require maintenance and periodical checking and for which it is desirable to have available certain processes for the partial dismantling of the insulation [fr

Thermal Analysis of Solar Panels

Science.gov (United States)

Barth, Nicolas; de Correia, João Pedro Magalhães; Ahzi, Saïd; Khaleel, Mohammad Ahmed

In this work, we propose to analyze the thermal behavior of PV panels using finite element simulations (FEM). We applied this analysis to compute the temperature distribution in a PV panel BP 350 subjected to different atmospheric conditions. This analysis takes into account existing formulations in the literature and, based on NOCT conditions, meteorological data was used to validate our approach for different wind speed and solar irradiance. The electrical performance of the PV panel was also studied. The proposed 2D FEM analysis is applied to different region's climates and was also used to consider the role of thermal inertia on the optimization of the PV device efficiency.

Using archetypes to create user panels for usability studies: Streamlining focus groups and user studies.

Science.gov (United States)

Stavrakos, S-K; Ahmed-Kristensen, S; Goldman, T

2016-09-01

Designers at the conceptual phase of products such as headphones, stress the importance of comfort, e.g. executing comfort studies and the need for a reliable user panel. This paper proposes a methodology to issue a reliable user panel to represent large populations and validates the proposed framework to predict comfort factors, such as physical fit. Data of 200 heads was analyzed by forming clusters, 9 archetypal people were identified out of a 200 people's ear database. The archetypes were validated by comparing the archetypes' responses on physical fit against those of 20 participants interacting with 6 headsets. This paper suggests a new method of selecting representative user samples for prototype testing compared to costly and time consuming methods which relied on the analysis of human geometry of large populations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Longitudinal MRI Study of Cortical Development through Early Childhood in Autism

Science.gov (United States)

Schumann, C.M.; Bloss, C.S.; Barnes, C. Carter; Wideman, G.M.; Carper, R.A.; Akshoomoff, N.; Pierce, K.; Hagler, D.; Schork, N.; Lord, C.; Courchesne, E.

2010-01-01

Cross-sectional MRI studies have long hypothesized that the brain in children with autism undergoes an abnormal growth trajectory that includes a period of early overgrowth; however this has never been confirmed by a longitudinal study. We carried out the first longitudinal study of brain growth in toddlers at the time symptoms of autism are becoming clinically apparent utilizing structural MRI scans at multiple time points beginning at 1.5 years up to 5 years of age. We collected 193 scans on 41 toddlers who received a confirmed diagnosis of Autistic Disorder at ~48 months of age and 44 typically developing controls. By 2.5 years of age, both cerebral gray and white matter was significantly enlarged in toddlers with Autistic Disorder, with the most severe enlargement occurring in frontal, temporal and cingulate cortices. In the longitudinal analyses, which we accounted for age and gender effect, we found that all regions (cerebral gray, cerebral white, frontal gray, temporal gray, cingulate gray, and parietal gray) except occipital gray developed at an abnormal growth rate in toddlers with Autistic Disorder that was mainly characterized by a quadratic age effect. Females with Autistic Disorder displayed a more pronounced abnormal growth profile in more brain regions than males with the disorder. Given that overgrowth clearly begins before 2 years of age, future longitudinal studies would benefit from inclusion of even younger populations as well as further characterization of genetic and other biomarkers in order to determine the underlying neuropathological processes causing the onset of autistic symptoms. PMID:20335478

Puncture panel optimization

International Nuclear Information System (INIS)

Glass, R.E.; Longenbaugh, R.S.

1986-01-01

Sandia National Laboratories developed the TRansUranic PACkage Transporter (TRUPACT) to transport defense contact-handled transuranic wastes. The package has been designed to meet the normal and hypothetical accident conditions in 10CFR71 which includes the demonstrated ability to survive a 1-meter drop onto a mild steel pin. The puncture protection is provided by puncture resistant panels. In conjunction with the development of TRUPACT, a series of experiments has been conducted to reduce the weight of the puncture resistant panels. The initial scoping tests resulted in a preliminary design incorporating 30 layers of Kevlar. This design has been shown to meet the regulatory puncture test. To reduce the weight of this panel, subscale tests were conducted on panels utilizing Kevlar yarns with varying mass per unit length (denier) as well as different resins. This paper reviews the testing undertaken in the original panel development and discusses the results obtained from the recent subscale and full-scale optimization tests

Parental mediation and cyberbullying - a longitudinal study.

Science.gov (United States)

Chng, Grace S; Liau, Albert; Khoo, Angeline; Li, Dongdong

2014-01-01

Parents use active and restrictive mediation strategies to guide and regulate children's online participation and the online risks they encounter. However, changes in parental mediation do occur over time and the effectiveness of these strategies on cyberbullying demands for further empirical investigation. The current study addresses these issues with a sample of 1084 students (49% girls) in a longitudinal, three-wave design. Gender differences were tested via multi-group analyses. Longitudinal growth models showed that parental use of both active and restrictive mediation decreased over time. For both types of mediation, the mean rate of change had a significant effect on boys' engagement in cyberbullying, but not for girls. Initial levels of restrictive mediation, but not active mediation, were found to be significantly predictive of cyberbullying in both genders. Girls had higher initial levels of both parental mediation types in comparison to boys. The results reveal that the effectiveness of active and restrictive mediation in relation to students' cyberbullying differs and informs us on gender differences. The implications of these results for parental education in online mediation are discussed.

Cavity Control and Panel Control Strategies in Double-Panel Structures for Transmitted Noise Reduction

NARCIS (Netherlands)

Ho, J.; Kalverboer, J.; Berkhoff, Arthur P.

2012-01-01

Investigation and comparisons of the cavity control and the panel control in a double-panel structure are presented in this paper. The double-panel structure, which comprises two panels with air in the gap, provides the advantages of low sound-transmission at high frequency, low heat-transmission

Hepatic (Liver) Function Panel

Science.gov (United States)

... Educators Search English Español Blood Test: Hepatic (Liver) Function Panel KidsHealth / For Parents / Blood Test: Hepatic (Liver) ... kidneys ) is working. What Is a Hepatic (Liver) Function Panel? A liver function panel is a blood ...

Robust block bootstrap panel predictability tests

NARCIS (Netherlands)

Westerlund, J.; Smeekes, S.

2013-01-01

Most panel data studies of the predictability of returns presume that the cross-sectional units are independent, an assumption that is not realistic. As a response to this, the current paper develops block bootstrap-based panel predictability tests that are valid under very general conditions. Some

Residents' perceptions of an integrated longitudinal curriculum: a qualitative study.

Science.gov (United States)

Lubitz, Rebecca; Lee, Joseph; Hillier, Loretta M

2015-01-01

The purpose of this study was to explore family medicine residents' perceptions of a newly restructured integrated longitudinal curriculum. A purposeful sample of 16 family medicine residents participated in focus group interviews conducted from a grounded theory perspective to identify the characteristics of this training model that contribute to and that challenge learning. Eight key themes were identified: continuity of care, relevance to family medicine, autonomy, program-focused preparation, professional development as facilitated by role modeling, patient volume, clarity of expectations for learners, and logistics. Positive learning experiences were marked by high levels of autonomy, continuity, and relevance to family medicine. Less favorable learning experiences were characterized by limited opportunities for continuity of care, limited relevance to family medicine practice and unclear expectations for the resident's role. Family physician-led learning experiences contributed to residents' understanding of the full scope of family medicine practice, more so than specialist-led experiences. The logistics of implementing the integrated block were challenging and negatively impacted continuity and learning. This study suggests that an integrated longitudinalized family medicine block training model has the potential to support the principles of a longitudinal integrated competency-based curriculum to effectively prepare residents for family medicine practice.

Panel Resonance Control and Cavity Control in Double-Panel Structures for Active Noise Reduction

NARCIS (Netherlands)

Ho, J.; Berkhoff, Arthur P.

2011-01-01

An analytical and experimental investigation of panel resonance control and cavity control in a double-panel structure is presented in this paper. The double-panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its low

Sound transmission loss of composite sandwich panels

Science.gov (United States)

Zhou, Ran

Light composite sandwich panels are increasingly used in automobiles, ships and aircraft, because of the advantages they offer of high strength-to-weight ratios. However, the acoustical properties of these light and stiff structures can be less desirable than those of equivalent metal panels. These undesirable properties can lead to high interior noise levels. A number of researchers have studied the acoustical properties of honeycomb and foam sandwich panels. Not much work, however, has been carried out on foam-filled honeycomb sandwich panels. In this dissertation, governing equations for the forced vibration of asymmetric sandwich panels are developed. An analytical expression for modal densities of symmetric sandwich panels is derived from a sixth-order governing equation. A boundary element analysis model for the sound transmission loss of symmetric sandwich panels is proposed. Measurements of the modal density, total loss factor, radiation loss factor, and sound transmission loss of foam-filled honeycomb sandwich panels with different configurations and thicknesses are presented. Comparisons between the predicted sound transmission loss values obtained from wave impedance analysis, statistical energy analysis, boundary element analysis, and experimental values are presented. The wave impedance analysis model provides accurate predictions of sound transmission loss for the thin foam-filled honeycomb sandwich panels at frequencies above their first resonance frequencies. The predictions from the statistical energy analysis model are in better agreement with the experimental transmission loss values of the sandwich panels when the measured radiation loss factor values near coincidence are used instead of the theoretical values for single-layer panels. The proposed boundary element analysis model provides more accurate predictions of sound transmission loss for the thick foam-filled honeycomb sandwich panels than either the wave impedance analysis model or the

BUCLASP 2: A computer program for instability analysis of biaxially loaded composite stiffened panels and other structures

Science.gov (United States)

Tripp, L. L.; Tamekuni, M.; Viswanathan, A. V.

1973-01-01

The use of the computer program BUCLASP2 is described. The program is intended for linear instability analyses of structures such as unidirectionally stiffened panels. Any structure that has a constant cross section in one direction, that may be idealized as an assemblage of beam elements and laminated flat and curved plant strip elements can be analyzed. The loadings considered are combinations of axial compressive loads and in-plane transverse loads. The two parallel ends of the panel must be simply supported and arbitrary elastic boundary conditions may be imposed along any one or both external longitudinal side. This manual consists of instructions for use of the program with sample problems, including input and output information. The theoretical basis of BUCLASP2 and correlations of calculated results with known solutions, are presented.

Longitudinal relations among parents' reactions to children's negative emotions, effortful control, and math achievement in early elementary school.

Science.gov (United States)

Swanson, Jodi; Valiente, Carlos; Lemery-Chalfant, Kathryn; Bradley, Robert H; Eggum-Wilkens, Natalie D

2014-01-01

Panel mediation models and fixed-effects models were used to explore longitudinal relations among parents' reactions to children's displays of negative emotions, children's effortful control (EC), and children's math achievement (N = 291; M age in fall of kindergarten = 5.66 years, SD = .39 year) across kindergarten through second grade. Parents reported their reactions and children's EC. Math achievement was assessed with a standardized achievement test. First-grade EC mediated the relation between parents' reactions at kindergarten and second-grade math achievement, beyond stability in constructs across study years. Panel mediation model results suggested that socialization of EC may be one method of promoting math achievement in early school; however, when all omitted time-invariant covariates of EC and math achievement were controlled, first-grade EC no longer predicted second-grade math achievement. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.

Changes in HRM in Europe: A Longitudinal Comparative Study among 18 European Countries

Science.gov (United States)

Nikandrou, Irene; Apospori, Eleni; Papalexandris, Nancy

2005-01-01

Purpose: To examine HRM strategies and practices and HRM position within organizations in various cultural, economic and sociopolitical contexts from a longitudinal perspective. Design/methodology/approach: The study uses the 1995 and 1999 Cranet data in a longitudinal methodological framework to explore the changes and trends in 18 European…

Performance comparison between silicon solar panel and dye-sensitized solar panel in Malaysia

Science.gov (United States)

Hamed, N. K. A.; Ahmad, M. K.; Urus, N. S. T.; Mohamad, F.; Nafarizal, N.; Ahmad, N.; Soon, C. F.; Ameruddin, A. S.; Faridah, A. B.; Shimomura, M.; Murakami, K.

2017-09-01

In carrying out experimental research in performance between silicon solar panel and dye-sensitive solar panel, we have been developing a device and a system. This system has been developed consisting of controllers, hardware and software. This system is capable to get most of the input sources. If only need to change the main circuit and coding for a different source input value. This device is able to get the ambient temperature, surface temperature, surrounding humidity, voltage with load, current with load, voltage without load and current without load and save the data into external memory. This device is able to withstand the heat and rain as it was fabricated in a waterproof box. This experiment was conducted to examine the performance of both the solar panels which are capable to maintain their stability and performance. A conclusion based on data populated, the distribution of data for dye-sensitized solar panel is much better than silicon solar panel as dye-sensitized solar panel is very sensitive to heat and not depend only on midday where is that is the maximum ambient temperature for both solar panel as silicon solar panel only can give maximum and high output only when midday.

Analysis of 3-panel and 4-panel microscale ionization sources

International Nuclear Information System (INIS)

Natarajan, Srividya; Parker, Charles B.; Glass, Jeffrey T.; Piascik, Jeffrey R.; Gilchrist, Kristin H.; Stoner, Brian R.

2010-01-01

Two designs of a microscale electron ionization (EI) source are analyzed herein: a 3-panel design and a 4-panel design. Devices were fabricated using microelectromechanical systems technology. Field emission from carbon nanotube provided the electrons for the EI source. Ion currents were measured for helium, nitrogen, and xenon at pressures ranging from 10 -4 to 0.1 Torr. A comparison of the performance of both designs is presented. The 4-panel microion source showed a 10x improvement in performance compared to the 3-panel device. An analysis of the various factors affecting the performance of the microion sources is also presented. SIMION, an electron and ion optics software, was coupled with experimental measurements to analyze the ion current results. The electron current contributing to ionization and the ion collection efficiency are believed to be the primary factors responsible for the higher efficiency of the 4-panel microion source. Other improvements in device design that could lead to higher ion source efficiency in the future are also discussed. These microscale ion sources are expected to find application as stand alone ion sources as well as in miniature mass spectrometers.

Numerical and experimental study on temperature control of solar panels with form-stable paraffin/expanded graphite composite PCM

International Nuclear Information System (INIS)

Luo, Zigeng; Huang, Zhaowen; Xie, Ning; Gao, Xuenong; Xu, Tao; Fang, Yutang; Zhang, Zhengguo

2017-01-01

Highlights: • A passive cooling PV-PCM system was developed. • Form-stable paraffin/EG composite PCM with high thermal conductivity was utilized. • Numerical simulation on the temperature of PV-PCM panel was carried out. • Effects of density were studied under the given weather conditions. - Abstract: Performance of photovoltaic (PV) panels is greatly affected by its operating temperature. And traditional active and passive cooling methods usually suffer from the disadvantages of external energy consumption, uneven temperature distribution and low thermal conductivity of phase change materials (PCMs). In this work, a PV-PCM system was developed to control the temperature of a PV panel by applying high thermal conductive form-stable paraffin (ZDJN-28)/EG composite PCM. The temperature, output voltage and power of a conventional PV panel and the PV-PCM panel were measured and compared. A numerical simulation model established by CFD software FLUENT was used to simulate the temperature change process of the PV-PCM panel with different material densities under the same conditions as experiment. The experiment results showed that compared with the temperature of the conventional PV panel, the temperature of the PV-PCM panel is kept below 50 °C for 200 min extended by 146 min with output power averagely increased by 7.28% in heating process. Simulated temperatures were in good agreement with experimental temperatures and indicated that the higher the density of the PCM is, the better the temperature management performance the PV panel could achieve. Besides, the PCM with density of 900 kg/m 3 was found sufficient to achieve a good temperature management performance when the average ambient temperature below 25 °C with the highest solar irradiation of 901 w/m 2 . In summary, this work is of great importance in the design of a PV-PCM system for temperature management of PV panels.

A prospective longitudinal study to estimate the prevalence of ...

African Journals Online (AJOL)

A prospective longitudinal study to estimate the prevalence of obesity in Egyptian children with nocturnal enuresis and the association between body mass index and ... Egyptian Journal of Medical Human Genetics ... Response to the treatment was evaluated statistically and correlated with body mass index percentile.

A Longitudinal Study on Learner Career Advancement in MOOCs

Science.gov (United States)

Wang, Yuan; Paquette, Luc; Baker, Ryan

2014-01-01

In this paper, we present progress towards a longitudinal study of the post-course career advancement of MOOC learners. We present initial results and analysis plans for how to link this to in-course behaviour, towards better understanding the goals of all MOOC learners.

Sound-proof Sandwich Panel Design via Metamaterial Concept

Science.gov (United States)

Sui, Ni

Sandwich panels consisting of hollow core cells and two face-sheets bonded on both sides have been widely used as lightweight and strong structures in practical engineering applications, but with poor acoustic performance especially at low frequency regime. Basic sound-proof methods for the sandwich panel design are spontaneously categorized as sound insulation and sound absorption. Motivated by metamaterial concept, this dissertation presents two sandwich panel designs without sacrificing weight or size penalty: A lightweight yet sound-proof honeycomb acoustic metamateiral can be used as core material for honeycomb sandwich panels to block sound and break the mass law to realize minimum sound transmission; the other sandwich panel design is based on coupled Helmholtz resonators and can achieve perfect sound absorption without sound reflection. Based on the honeycomb sandwich panel, the mechanical properties of the honeycomb core structure were studied first. By incorporating a thin membrane on top of each honeycomb core, the traditional honeycomb core turns into honeycomb acoustic metamaterial. The basic theory for such kind of membrane-type acoustic metamaterial is demonstrated by a lumped model with infinite periodic oscillator system, and the negative dynamic effective mass density for clamped membrane is analyzed under the membrane resonance condition. Evanescent wave mode caused by negative dynamic effective mass density and impedance methods are utilized to interpret the physical phenomenon of honeycomb acoustic metamaterials at resonance. The honeycomb metamaterials can extraordinarily improve low-frequency sound transmission loss below the first resonant frequency of the membrane. The property of the membrane, the tension of the membrane and the numbers of attached membranes can impact the sound transmission loss, which are observed by numerical simulations and validated by experiments. The sandwich panel which incorporates the honeycomb metamateiral as

Multilingualism and fMRI: Longitudinal Study of Second Language Acquisition

Science.gov (United States)

Andrews, Edna; Frigau, Luca; Voyvodic-Casabo, Clara; Voyvodic, James; Wright, John

2013-01-01

BOLD fMRI is often used for the study of human language. However, there are still very few attempts to conduct longitudinal fMRI studies in the study of language acquisition by measuring auditory comprehension and reading. The following paper is the first in a series concerning a unique longitudinal study devoted to the analysis of bi- and multilingual subjects who are: (1) already proficient in at least two languages; or (2) are acquiring Russian as a second/third language. The focus of the current analysis is to present data from the auditory sections of a set of three scans acquired from April, 2011 through April, 2012 on a five-person subject pool who are learning Russian during the study. All subjects were scanned using the same protocol for auditory comprehension on the same General Electric LX 3T Signa scanner in Duke University Hospital. Using a multivariate analysis of covariance (MANCOVA) for statistical analysis, proficiency measurements are shown to correlate significantly with scan results in the Russian conditions over time. The importance of both the left and right hemispheres in language processing is discussed. Special attention is devoted to the importance of contextualizing imaging data with corresponding behavioral and empirical testing data using a multivariate analysis of variance. This is the only study to date that includes: (1) longitudinal fMRI data with subject-based proficiency and behavioral data acquired in the same time frame; and (2) statistical modeling that demonstrates the importance of covariate language proficiency data for understanding imaging results of language acquisition. PMID:24961428

Multilingualism and fMRI: Longitudinal Study of Second Language Acquisition

Directory of Open Access Journals (Sweden)

John Wright

2013-05-01

Full Text Available BOLD fMRI is often used for the study of human language. However, there are still very few attempts to conduct longitudinal fMRI studies in the study of language acquisition by measuring auditory comprehension and reading. The following paper is the first in a series concerning a unique longitudinal study devoted to the analysis of bi- and multilingual subjects who are: (1 already proficient in at least two languages; or (2 are acquiring Russian as a second/third language. The focus of the current analysis is to present data from the auditory sections of a set of three scans acquired from April, 2011 through April, 2012 on a five-person subject pool who are learning Russian during the study. All subjects were scanned using the same protocol for auditory comprehension on the same General Electric LX 3T Signa scanner in Duke University Hospital. Using a multivariate analysis of covariance (MANCOVA for statistical analysis, proficiency measurements are shown to correlate significantly with scan results in the Russian conditions over time. The importance of both the left and right hemispheres in language processing is discussed. Special attention is devoted to the importance of contextualizing imaging data with corresponding behavioral and empirical testing data using a multivariate analysis of variance. This is the only study to date that includes: (1 longitudinal fMRI data with subject-based proficiency and behavioral data acquired in the same time frame; and (2 statistical modeling that demonstrates the importance of covariate language proficiency data for understanding imaging results of language acquisition.

Multilingualism and fMRI: Longitudinal Study of Second Language Acquisition.

Science.gov (United States)

Andrews, Edna; Frigau, Luca; Voyvodic-Casabo, Clara; Voyvodic, James; Wright, John

2013-05-28

BOLD fMRI is often used for the study of human language. However, there are still very few attempts to conduct longitudinal fMRI studies in the study of language acquisition by measuring auditory comprehension and reading. The following paper is the first in a series concerning a unique longitudinal study devoted to the analysis of bi- and multilingual subjects who are: (1) already proficient in at least two languages; or (2) are acquiring Russian as a second/third language. The focus of the current analysis is to present data from the auditory sections of a set of three scans acquired from April, 2011 through April, 2012 on a five-person subject pool who are learning Russian during the study. All subjects were scanned using the same protocol for auditory comprehension on the same General Electric LX 3T Signa scanner in Duke University Hospital. Using a multivariate analysis of covariance (MANCOVA) for statistical analysis, proficiency measurements are shown to correlate significantly with scan results in the Russian conditions over time. The importance of both the left and right hemispheres in language processing is discussed. Special attention is devoted to the importance of contextualizing imaging data with corresponding behavioral and empirical testing data using a multivariate analysis of variance. This is the only study to date that includes: (1) longitudinal fMRI data with subject-based proficiency and behavioral data acquired in the same time frame; and (2) statistical modeling that demonstrates the importance of covariate language proficiency data for understanding imaging results of language acquisition.

Stability and change in adult personality over 6 years: findings from the Victoria Longitudinal Study.

Science.gov (United States)

Small, Brent J; Hertzog, Christopher; Hultsch, David F; Dixon, Roger A

2003-05-01

Data from the Victoria Longitudinal Study were used to examine the 6-year longitudinal stability of personality in older adults. Personality was measured with the NEO Personality Inventory. The longitudinal sample consisted of 223 adults initially ranging from 55 to 85 years of age. Longitudinal confirmatory factor analyses were used to examine the stability of individual differences in change over time, and the stability of the longitudinal factor structure. The results indicated both substantial stability at the level of individual differences in change, as well as significant individual differences in change that were related to age and gender. Finally, the factor structure of personality was invariant over time but did not approximate simple structure for the five dimensions of personality. Our study of 6-year personality development provided both (a). a confirmation of early significant stability findings and (b). unique evidence for significant individual differences in late adulthood.

Antinuclear antibody panel

Science.gov (United States)

... page: //medlineplus.gov/ency/article/003535.htm Antinuclear antibody panel To use the sharing features on this page, please enable JavaScript. The antinuclear antibody panel is a blood test that looks at ...

Hepatitis virus panel

Science.gov (United States)

... page: //medlineplus.gov/ency/article/003558.htm Hepatitis virus panel To use the sharing features on this page, please enable JavaScript. The hepatitis virus panel is a series of blood tests used ...

REINFORCED COMPOSITE PANEL

DEFF Research Database (Denmark)

2003-01-01

A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing rein...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

Exploring Longitudinal Risk-return Relationships

DEFF Research Database (Denmark)

Andersen, Torben J.; Bettis, Richard A.

2015-01-01

We study a longitudinal fit model of adaptation and its association with the longitudinal risk-return relationship. The model allows the firm to adjust its position in response to partial learning about a changing environment characterized by two path-dependent processes—a random walk and a stoch......We study a longitudinal fit model of adaptation and its association with the longitudinal risk-return relationship. The model allows the firm to adjust its position in response to partial learning about a changing environment characterized by two path-dependent processes—a random walk...... can lead to the inverse longitudinal risk-return relationships observed empirically. We discuss this apparent paradox and the possible resolution between mindless and conscious behavior as plausible causes of the longitudinal Bowman Paradox....

Always connected: a longitudinal field study of mobile communication

NARCIS (Netherlands)

Peters, O.; Ben Allouch, Soumaya

2005-01-01

Twenty-five novice users of a new mobile communication device were closely tracked for a period of three months. The results of this longitudinal field study show that people’s motivations for using mobile communication technology are initially influenced more strongly by their perceptions about the

The Dynamic Interplay among Maternal Empathy, Quality of Mother-Adolescent Relationship, and Adolescent Antisocial Behaviors: New Insights from a Six-Wave Longitudinal Multi-Informant Study.

Directory of Open Access Journals (Sweden)

Elisabetta Crocetti

Full Text Available Adolescents' behavior is often a matter of concern, given their increased likelihood of enacting antisocial behaviors, which cause disruptions in the social order and are potentially harmful for the adolescents themselves and for the people around them. In this six-wave longitudinal study we sought to examine the interplay among maternal empathy, multiple indicators of mother-adolescent relationship quality (i.e., balanced relatedness, conflict, and support, and adolescent antisocial behaviors rated both by adolescents and their mothers. Participants for the current study were 497 Dutch adolescents (56.9% males followed from age 13 to 18, and their mothers. A series of cross-lagged panel models revealed reciprocal associations between maternal empathy and mother-adolescent relationship quality and between mother-adolescent relationship quality and adolescent antisocial behaviors. Interestingly, we also found some indirect effects of adolescent antisocial behaviors on maternal empathy mediated by mother-adolescent relationship quality. Overall, this study further highlights a process of reciprocal influences within mother-adolescent dyads.

The Dynamic Interplay among Maternal Empathy, Quality of Mother-Adolescent Relationship, and Adolescent Antisocial Behaviors: New Insights from a Six-Wave Longitudinal Multi-Informant Study

Science.gov (United States)

Crocetti, Elisabetta; Moscatelli, Silvia; Van der Graaff, Jolien; Keijsers, Loes; van Lier, Pol; Koot, Hans M.; Rubini, Monica; Meeus, Wim; Branje, Susan

2016-01-01

Adolescents’ behavior is often a matter of concern, given their increased likelihood of enacting antisocial behaviors, which cause disruptions in the social order and are potentially harmful for the adolescents themselves and for the people around them. In this six-wave longitudinal study we sought to examine the interplay among maternal empathy, multiple indicators of mother-adolescent relationship quality (i.e., balanced relatedness, conflict, and support), and adolescent antisocial behaviors rated both by adolescents and their mothers. Participants for the current study were 497 Dutch adolescents (56.9% males) followed from age 13 to 18, and their mothers. A series of cross-lagged panel models revealed reciprocal associations between maternal empathy and mother-adolescent relationship quality and between mother-adolescent relationship quality and adolescent antisocial behaviors. Interestingly, we also found some indirect effects of adolescent antisocial behaviors on maternal empathy mediated by mother-adolescent relationship quality. Overall, this study further highlights a process of reciprocal influences within mother-adolescent dyads. PMID:26990191

Rational Design of Composite Panels

DEFF Research Database (Denmark)

Riber, Hans Jørgen

1996-01-01

A non-linear structural model for composite panels is presented. The non-linear terms in the lateral displacements are modelled as an additional set of lateral loads acting on the panel. Hence the solution is reduced to that of an equivalent panel with small displacements In order to treat sandwich...... Norske Veritas', DNV, building rules concerning high-speed light craft, in which the panel scantlings are often restricted by a maximum lateral deflection connected with the panel span....

Performance of patch repaired composite panels under fatigue loads

International Nuclear Information System (INIS)

Darwish, Feras H.; Hamoush, S.; Shivakumar, K.

2006-01-01

This paper evaluates the performance of bonded patch-scarf repairs of full scale laminated composite panels under cyclic load conditions. Nondestructive testing to characterize the quality of repairs and destructive testing to evaluate the performance of repaired panels were used in this study. Carbon/Epoxy prepreg material used was used to lay up six-ply (12 in. x 27 in. /305x686mm) (-60/60/0) s quasi-isotropic laminates. 7-ply scarf repair with a gradient of 0.5 inch (12.7mm) per layer was used to perform the repair of a damaged zone. The patch consisted of 7.5 inches (190mm) diameter adhesive film, 1 inch (25.4mm) diameter filler ply at 90fiber orientation, and six plies (2-7 inches (51-178mm) diameter) to match the lay-up of the parent material. The study was extended to include defective repairs. The defect was engineered by inserting a 1 inch (25.4 mm) circular Teflon flaw between the fifth and sixth layers of the patch. A total of 28 panels were prepared and divided into five categories: (1) three pristine panels (undamaged parental materials); (2) three damaged panels (1-inch-centered-hole); (3) two repaired panels with wrong fiber orientation; (4) nine good repaired panels, and (5) eleven defective repair panels (1 inch flaw). A nondestructive evaluation to check the conditions of the repairs was performed on most of the tested panels that include the pulse-echo C-scan and pseudo through transmission air coupled and water coupled C-scan. Based on the results of the experimental evaluation of this study, good repair restored 95% of the tensile strength while defective repair restored 90% of the tensile strength of the pristine panels. Under fatigue loading, panels repaired with a 1 inch delamination flaw within the patch layers showed a major reduction in fatigue life compared to the good repair panels under similar loading conditions. (author)

Stress Process of Illicit Drug Use among U.S. Immigrants' Adolescent Children: A Longitudinal Study

Science.gov (United States)

Choo, Hyekyung

2012-01-01

This study examined a full path model of stress process for predicting illicit drug use among Asian and Latino immigrants' adolescent children. Using 2-year longitudinal data (National Longitudinal Study of Adolescent Health) from a sample of adolescents with Asian or Latino immigrant parents (N = 2,353), the study explored structural…

Panel Unit Root Tests by Combining Dependent Values: A Comparative Study

Directory of Open Access Journals (Sweden)

Xuguang Sheng

2011-01-01

Full Text Available We conduct a systematic comparison of the performance of four commonly used value combination methods applied to panel unit root tests: the original Fisher test, the modified inverse normal method, Simes test, and the modified truncated product method (TPM. Our simulation results show that under cross-section dependence the original Fisher test is severely oversized, but the other three tests exhibit good size properties. Simes test is powerful when the total evidence against the joint null hypothesis is concentrated in one or very few of the tests being combined, but the modified inverse normal method and the modified TPM have good performance when evidence against the joint null is spread among more than a small fraction of the panel units. These differences are further illustrated through one empirical example on testing purchasing power parity using a panel of OECD quarterly real exchange rates.

Creep Behavior of Structural Insulated Panels (SIPS): Results from a Pilot Study

Science.gov (United States)

Dwight McDonald; Marshall Begel; C. Adam Senalik; Robert Ross; Thomas D. Skaggs; Borjen Yeh; Thomas Williamson

2014-01-01

Structural insulated panels (SIPs) have been recognized as construction materials in the International Residential Code (IRC) since 2009. Although most SIPs are used in wall applications, they can also be used as roof or floor panels that are subjected to long-term transverse loading, for which SIP creep performance may be critical in design. However, limited...

Supersonic Panel Flutter Test Results for Flat Fiber-Glass Sandwich Panels with Foamed Cores

Science.gov (United States)

Tuovila, W. J.; Presnell, John G., Jr.

1961-01-01

Flutter tests have been made on flat panels having a 1/4 inch-thick plastic-foam core covered with thin fiber-glass laminates. The testing was done in the Langley Unitary Plan wind tunnel at Mach numbers from 1.76 t o 2.87. The flutter boundary for these panels was found to be near the flutter boundary of thin metal panels when compared on the basis of an equivalent panel stiffness. The results also demonstrated that the depth of the cavity behind the panel has a pronounced influence on flutter. Changing the cavity depth from 1 1/2 inches to 1/2 inch reduced the dynamic pressure at start of flutter by 40 percent. No flutter was obtained when the spacers on the back of the panel were against the bottom of the cavity.

Panel Resource Management (PRM) Implementation and Effects within Safety Review Panel Settings and Dynamics

Science.gov (United States)

Taylor, Robert W.; Nash, Sally K.

2007-01-01

While technical training and advanced degree's assure proficiency at specific tasks within engineering disciplines, they fail to address the potential for communication breakdown and decision making errors familiar to multicultural environments where language barriers, intimidating personalities and interdisciplinary misconceptions exist. In an effort to minimize these pitfalls to effective panel review, NASA's lead safety engineers to the ISS Safety Review Panel (SRP), and Payload Safety Review Panel (PSRP) initiated training with their engineers, in conjunction with the panel chairs, and began a Panel Resource Management (PRM) program. The intent of this program focuses on the ability to reduce the barriers inhibiting effective participation from all panel attendees by bolstering participants confidence levels through increased communication skills, situational awareness, debriefing, and a better technical understanding of requirements and systems.

The Australian longitudinal study on male health-methods

Directory of Open Access Journals (Sweden)

Dianne Currier

2016-10-01

Full Text Available Abstract Background The Australian Longitudinal Study on Male Health (Ten to Men was established in 2011 to build the evidence base on male health to inform policy and program development. Methods Ten to Men is a national longitudinal study with a stratified multi-stage cluster random sample design and oversampling in rural and regional areas. Household recruitment was conducted from October 2013 to July 2014. Males who were aged 10 to 55 years residing in private dwellings were eligible to participate. Data were collected via self-completion paper questionnaires (participants aged 15 to 55 and by computer-assisted personal interview (boys aged 10 to 14. Household and proxy health data for boys were collected from a parent via a self-completion paper-based questionnaire. Questions covered socio-demographics, health status, mental health and wellbeing, health behaviours, social determinants, and health knowledge and service use. Results A cohort of 15,988 males aged between 10 and 55 years was recruited representing a response fraction of 35 %. Conclusion Ten to Men is a unique resource for investigating male health and wellbeing. Wave 1 data are available for approved research projects.

Development of a panel of genome-wide ancestry informative markers to study admixture throughout the Americas.

Directory of Open Access Journals (Sweden)

Joshua Mark Galanter

Full Text Available Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R² > 0.9 for ancestral components with significant between-subject variance. Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region.

Solar panel cleaning robot

Science.gov (United States)

Nalladhimmu, Pavan Kumar Reddy; Priyadarshini, S.

2018-04-01

As the demand of electricity is increasing, there is need to using the renewable sources to produce the energy at present of power shortage, the use of solar energy could be beneficial to great extent and easy to get the maximum efficiency. There is an urgent in improving the efficiency of solar power generation. Current solar panels setups take a major power loss when unwanted obstructions cover the surface of the panels. To make solar energy more efficiency of solar array systems must be maximized efficiency evaluation of PV panels, that has been discussed with particular attention to the presence of dust on the efficiency of the PV panels have been highlighted. This paper gives the how the solar panel cleaning system works and designing of the cleaning system.

Lightweight, Thermally Insulating Structural Panels

Science.gov (United States)

Eisen, Howard J.; Hickey, Gregory; Wen, Liang-Chi; Layman, William E.; Rainen, Richard A.; Birur, Gajanana C.

1996-01-01

Lightweight, thermally insulating panels that also serve as structural members developed. Honeycomb-core panel filled with low-thermal-conductivity, opacified silica aerogel preventing convection and minimizes internal radiation. Copper coating on face sheets reduces radiation. Overall thermal conductivities of panels smaller than state-of-art commercial non-structurally-supporting foam and fibrous insulations. On Earth, panels suitable for use in low-air-pressure environments in which lightweight, compact, structurally supporting insulation needed; for example, aboard high-altitude aircraft or in partially evacuated panels in refrigerators.

PERBANDINGAN UNJUK KERJA ANTARA PANEL SEL SURYA BERPENJEJAK DENGAN PANEL SEL SURYA DIAM

OpenAIRE

Syafaruddin Ch

2010-01-01

The ability to produce electrical energy at Solar Power Plant  is highly dependent on the magnitude and duration of sun exposure on the solar cell panels. The movement of the sun from east to west that periodicity in every day is a problem at  the  optimization generation of electricity at  Solar Power Plant   if using solar panel that motionless. This is because the solar cell panel can not catch the maximum sun exposure. To solve the above problem then designed a solar cell panel  tracker...

Failure of uniformly compression loaded debond damaged sandwich panels — An experimental and numerical study

DEFF Research Database (Denmark)

Moslemian, Ramin; Quispitupa, Amilcar; Berggreen, Christian

2012-01-01

This paper deals with the failure of compression-loaded sandwich panels with an implanted circular face/core debond. Uniform compression tests were conducted on intact sandwich panels with three different types of core material (H130, H250 and PMI) and on similar panels with circular face...

Ultrafast X-ray absorption study of longitudinal-transverse phonon coupling in electrolyte aqueous solution

DEFF Research Database (Denmark)

Jiao, Yishuo; Adams, Bernhard W.; Dohn, Asmus Ougaard

2017-01-01

Ultrafast X-ray absorption spectroscopy is applied to study the conversion of longitudinal to transverse phonons in aqueous solution. Permanganate solutes serve as X-ray probe molecules that permit the measurement of the conversion of 13.5 GHz, longitudinal phonons to 27 GHz, transverse phonons...

Experimental and numerical results from hybrid retrofitted photovoltaic panels

International Nuclear Information System (INIS)

Rossi, Cecilia; Tagliafico, Luca A.; Scarpa, Federico; Bianco, Vincenzo

2013-01-01

Highlights: • The experimental study focuses on the feasibility of hybrid PV/T panels retrofitting. • The critical role of a thin layer of air between PV panel and back plate is evidenced. • The benefit of the addition of a conductive paste layer is analyzed via FEM simulations. • The use of wood ribs to stick the back plate represents a cheap effective solution. - Abstract: The aim of present study is to investigate different methodologies to achieve a better contact between a photovoltaic panel and a thermal plate, in order to cool the PV panel by means of water in the perspective of coupling it with a heat pump. It is believed that this kind of system allows to obtain a higher energy efficiency. The analysis is developed both experimentally and numerically, testing different kinds of configurations in different operating conditions. Simulations are employed to analyze the effect of the variations of the contact resistance between the panel and the thermal plates, demonstrating that the use of a conductive paste increases the overall performance of the panel. Results show interesting possibilities in terms of retrofitting of existing photovoltaic panels by employing very simple solutions, such as to fix the thermal plate on the rear of the panel by means of wood ribs

Air pollution and respiratory health of children: the PEACE panel study in Katowice, Poland.

NARCIS (Netherlands)

Niepsuj, G.; Niepsuj, K.; Nieroda-Muller, A.; Rauer, R.; Krzywiecki, Z.; Borowska, M.; Hlawiczka, Z.; Brunekreef, B.

1998-01-01

This study was carried out within the framework of the multicentre Pollution Effects on Asthmatic Children in Europe (PEACE) project. Two panels of mildly asthmatic children were studied. Seventy two children living in the Upper Silesia (the largest Polish industrial agglomeration) and 73 children

Secondary Analysis of National Longitudinal Transition Study 2 Data

Science.gov (United States)

Hicks, Tyler A.; Knollman, Greg A.

2015-01-01

This review examines published secondary analyses of National Longitudinal Transition Study 2 (NLTS2) data, with a primary focus upon statistical objectives, paradigms, inferences, and methods. Its primary purpose was to determine which statistical techniques have been common in secondary analyses of NLTS2 data. The review begins with an…

Panel data analysis using EViews

CERN Document Server

Agung, I Gusti Ngurah

2013-01-01

A comprehensive and accessible guide to panel data analysis using EViews software This book explores the use of EViews software in creating panel data analysis using appropriate empirical models and real datasets. Guidance is given on developing alternative descriptive statistical summaries for evaluation and providing policy analysis based on pool panel data. Various alternative models based on panel data are explored, including univariate general linear models, fixed effect models and causal models, and guidance on the advantages and disadvantages of each one is given. Panel Data Analysis

Studying impact damage on carbon-fiber reinforced aircraft composite panels with sonicir

International Nuclear Information System (INIS)

Han Xiaoyan; Zhang Ding; He Qi; Song Yuyang; Lubowicki, Anthony; Zhao Xinyue; Newaz, Golam.; Favro, Lawrence D.; Thomas, Robert L.

2011-01-01

Composites are becoming more important materials in commercial aircraft structures such as the fuselage and wings with the new B787 Dreamliner from Boeing which has the target to utilize 50% by weight of composite materials. Carbon-fiber reinforced composites are the material of choice in aircraft structures. This is due to their light weight and high strength (high strength-to-weight ratio), high specific stiffness, tailorability of properties, design flexibility etc. Especially, by reducing the aircraft's body weight by using such lighter structures, the cost of fuel can be greatly reduced with the high jet fuel price for commercial airlines. However, these composites are prone to impact damage and the damage may occur without any observable sign on the surface, yet resulting in delaminations and disbonds that may occur well within the layers. We are studying the impact problem with carbon-fiber reinforced composite panels and developing SonicIR for this application as a fast and wide-area NDE technology. In this paper, we present our results in studying composite structures including carbon-fiber reinforced composite materials, and preliminary quantitative studies on delamination type defect depth identification in the panels.

Study of thermosiphon and radiant panel passive heating systems for metal buildings

Energy Technology Data Exchange (ETDEWEB)

Biehl, F.A.; Schnurr, N.M.; Wray, W.O.

1983-01-01

A study of passive-heating systems appropriate for use on metal buildings is being conducted at Los Alamos National Laboratory for the Naval Civil Engineering Laboratory, Port Hueneme, California. The systems selected for study were chosen on the basis of their appropriateness for retrofit applications, although they are also suitable for new construction: simple radiant panels that communicate directly with the building interior and a backflow thermosiphon that provides heat indirectly.

RECIPANEL: RECYCLED PAPER PANELS

Directory of Open Access Journals (Sweden)

HERNÁN CAÑOLA

2012-01-01

Full Text Available En este artículo se estudia la fabricación y el comportamiento mecánico de paneles a base de papel reciclado. El objetivo principal del proyecto es producir un prototipo de panel que emplee elementos provenientes de residuos sólidos (papel periódico y de un material conglomerante (cemento Portland blanco. El panel debe ser económico, debe tener buenas propiedades mecánicas y debe tener dimensiones comerciales para su uso en muros tabiques y en cielos falsos en la industria de la construcción. El Recipanel es un panel no estructural a base de papel reciclado. El Recipanel cumple las normas colombianas en lo relativo a los paneles de uso no estructural y presenta además unas excelentes características mecánicas.

Which emotional regulatory strategy makes Chinese adolescents happier? A longitudinal study

NARCIS (Netherlands)

Sang, B.; Deng, X.; Luan, Z.

2014-01-01

Growing interest in emotion regulation is reflected in the studies of cognitive and social development. However, the extant studies mainly highlight how emotion regulation develops based on a western value system. This study utilised a longitudinal design to examine the development of emotion

SCI Longitudinal Aging Study: 40 Years of Research.

Science.gov (United States)

Krause, James S; Clark, Jillian M R; Saunders, Lee L

2015-01-01

The Spinal Cord Injury (SCI) Longitudinal Aging Study was initiated in 1973 and has conducted 8 assessments over the past 40 years. It was designed to help rehabilitation professionals understand the life situation of people with SCI, but it has developed into the most long-standing study of aging and SCI and has resulted in over 50 publications. Our purpose was to provide a detailed history of the study, response patterns, utilization of measures, and a summary of key findings reported in the literature. Five participant samples have been incorporated over the 40 years, with enrollment in 1973, 1984, 1993 (2 samples), and 2003. A total of 2,208 participants have completed 6,001 assessments, with a particularly large number of assessments among those who are more than 40 years post injury (n = 349). The overall results have indicated changing patterns of outcomes over time as persons with SCI age, with some notable declines in participation and health. There has been a survivor effect whereby persons who are more active, well-adjusted, and healthier live longer. This study has several important features that are required for longitudinal research including (a) consistency of follow-up, (b) consistency of measures over time, (c) addition of new participant samples to counteract attrition, and (d) inclusion of a large number of individuals who have reached aging milestones unparalleled in the literature. Data from this study can inform the literature on the natural course of aging with SCI.

Longitudinal prediction of divorce in Russia: the role of individual and couple drinking patterns.

Science.gov (United States)

Keenan, Katherine; Kenward, Michael G; Grundy, Emily; Leon, David A

2013-01-01

The aim of the study was to explore associations between dimensions of alcohol use in married couples and subsequent divorce in Russia using longitudinal data. Follow-up data on 7157 married couples were extracted from 14 consecutive annual rounds (1994-2010) of the Russian Longitudinal Monitoring Survey, a national population-based panel study. Discrete-time hazard models were fitted to estimate the probability of divorce among married couples by drinking patterns reported in the previous survey wave. In adjusted models, increased odds of divorce were associated with greater frequency of husband and wife drinking (test for trend P = 0.005, and P = 0.05, respectively), wife's binge drinking (P = 0.05) and husband's heavy vodka drinking (P = 0.005). Couples in whom the wife drank more frequently than the husband were more likely to divorce (OR 2.86, 95% CI 1.52-5.36), compared with other combinations of drinking. The association between drinking and divorce was stronger in regions outside Moscow or St. Petersburg. This study adds to the sparse literature on the topic and suggests that in Russia heavy and frequent drinking of both husbands and wives put couples at greater risk of future divorce, with some variation by region and aspect of alcohol use.

Personality, work characteristics, and employee well-being: a longitudinal analysis of additive and moderating effects.

Science.gov (United States)

Houkes, Inge; Janssen, Peter P M; de Jonge, Jan; Bakker, Arnold B

2003-01-01

This study tested the longitudinal influence of personality (measured by the characteristics growth need strength, negative affectivity [NA], and upward striving) on 3 psychological outcomes (intrinsic work motivation, emotional exhaustion, and turnover intention), using a pattern of specific relationships between work characteristics and these outcomes as a framework. The study hypotheses were tested in a multioccupational sample consisting of bank employees and teachers, using a 2-wave panel design with a 1-year time interval and structural equation modeling. NA had a cross-lagged direct and additive relationship with emotional exhaustion and also moderated the relationship between Time 1 workload and Time 2 emotional exhaustion. The authors concluded that NA may have multiple effects on emotional exhaustion that persist over time.

Predicting panel scores by linguistic analysis

Energy Technology Data Exchange (ETDEWEB)

Van den Besselaar, P.; Stout, L.; Gou, X

2016-07-01

In this paper we explore the use of text analysis for deriving quality indicators of project proposals. We do full text analysis of 3030 review reports. After term extraction, we aggregate the term occurrences to linguistic categories. Using thse linguistic categories as independent variables, we study how well these predict the grading by the review panels. Together, the different linguistic categories explain about 50% of the variance in the grading of the applications. The relative importance of the different linguistic categories inform us about the way the panels work. This can be used to develop altmetrics for the quality of the peer and panel review processes. (Author)

Make Your Own Solar Panel.

Science.gov (United States)

Suzuki, David

1992-01-01

Presents an activity in which students make a simulated solar panel to learn about the principles behind energy production using solar panels. Provides information about how solar panels function to produce energy. (MCO)

Design scenarios for flat panel photobioreactors

International Nuclear Information System (INIS)

Slegers, P.M.; Wijffels, R.H.; Straten, G. van; Boxtel, A.J.B. van

2011-01-01

Evaluation of the potential of algae production for biofuel and other products at various locations throughout the world requires assessment of algae productivity under varying light conditions and different reactor layouts. A model was developed to predict algae biomass production in flat panel photobioreactors using the interaction between light and algae growth for the algae species Phaeodactylum tricornutum and Thalassiosira pseudonana. The effect of location, variable sunlight and reactor layout on biomass production in single standing and parallel positioned flat panels was considered. Three latitudes were studied representing the Netherlands, France and Algeria. In single standing reactors the highest yearly biomass production is achieved in Algeria. During the year biomass production fluctuates the most in the Netherlands, while it is almost constant in Algeria. Several combinations of path lengths and biomass concentrations can result in the same optimal biomass production. The productivity in parallel place flat panels is strongly influenced by shading and diffuse light penetration between the panels. Panel orientation has a large effect on productivity and at higher latitudes the difference between north-south and east-west orientation may go up to 50%.

A Longitudinal Study of Children's Social Behaviors and Their Causal Relationship to Reading Growth

Science.gov (United States)

Lim, Hyo Jin; Kim, Junyeop

2011-01-01

This paper aims at investigating the causal effects of social behaviors on subsequent reading growth in elementary school, using the "Early Childhood Longitudinal Study-Kindergarten" ("ECLS-K") data. The sample was 8,869 subjects who provided longitudinal measures of reading IRT scores from kindergarten (1998-1999) to fifth…

Solar panel parallel mounting configuration

Science.gov (United States)

Mutschler, Jr., Edward Charles (Inventor)

1998-01-01

A spacecraft includes a plurality of solar panels interconnected with a power coupler and an electrically operated device to provide power to the device when the solar cells are insolated. The solar panels are subject to bending distortion when entering or leaving eclipse. Spacecraft attitude disturbances are reduced by mounting each of the solar panels to an elongated boom made from a material with a low coefficient of thermal expansion, so that the bending of one panel is not communicated to the next. The boom may be insulated to reduce its bending during changes in insolation. A particularly advantageous embodiment mounts each panel to the boom with a single mounting, which may be a hinge. The single mounting prevents transfer of bending moments from the panel to the boom.

The Relationships of Expectancies With E-cigarette Use Among Hospitalized Smokers: A Prospective Longitudinal Study.

Science.gov (United States)

Hendricks, Peter S; Thorne, Christopher B; Lappan, Sara N; Sweat, Noah W; Cheong, JeeWon; Ramachandran, Rekha; Kohler, Connie L; Bailey, William C; Harrington, Kathleen F

2018-01-05

Expectancies demonstrate cross-sectional associations with e-cigarette use, but the prospective relationships between expectancies and e-cigarette use are unknown. This study examined the longitudinal associations of expectancies with e-cigarette use among hospitalized tobacco cigarette smokers. E-cigarette expectancies (e-cigarette-specific Brief Smoking Consequences Questionnaire-Adult [BSCQ-A]), tobacco cigarette expectancies (tobacco-specific BSCQ-A), and number of days used e-cigarettes in the past 30 days were assessed at baseline hospitalization, 6-months post-hospitalization, and 12-months post-hospitalization among 978 hospitalized tobacco cigarette smokers. Expectancy difference scores (e-cigarette-specific expectancies minus tobacco-specific expectancies) were computed for each of the 10 BSCQ-A scales. Cross-lagged panel models tested the relationships between expectancy difference scores and number of days used e-cigarettes in the past 30 days for each of the 10 BSCQ-A scales. Though some models revealed partial associations between expectancies and e-cigarette use, only one yielded results consistent with hypotheses. Greater e-cigarette use at baseline predicted greater expectancies that e-cigarettes taste pleasant as compared to tobacco cigarettes at 6 months, which then predicted greater e-cigarette use at 12 months. To a lesser degree greater expectancies that e-cigarettes taste pleasant as compared to tobacco cigarettes at baseline predicted greater e-cigarette use at 6 months, which then predicted greater expectancies that e-cigarettes taste pleasant as compared to tobacco cigarettes at 12 months. Expectancies that e-cigarettes provide similar or more pleasant taste sensations as compared to tobacco cigarettes may be both a cause and consequence of e-cigarette use. Focusing on the taste experience may prove most effective in modifying e-cigarette use behavior. The current study offers the first longitudinal examination of expectancies and e

Monitoring of fetuses with intrauterine growth restriction: a longitudinal study

NARCIS (Netherlands)

Hecher, K.; Bilardo, C. M.; Stigter, R. H.; Ville, Y.; Hackelöer, B. J.; Kok, H. J.; Senat, M. V.; Visser, G. H.

2001-01-01

To describe the time sequence of changes in fetal monitoring variables in intrauterine growth restriction and to correlate these findings with fetal outcome at delivery. This was a prospective longitudinal observational multicenter study on 110 singleton pregnancies with growth-restricted fetuses

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2015. Scientific Opinion on Dietary Reference Values for phosphorus

DEFF Research Database (Denmark)

Tetens, Inge

2015-01-01

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies derived Dietary Reference Values (DRVs) for phosphorus. The Panel considered data from balance studies, losses of phosphorus from the body and intestinal absorption for possible use in a fact......Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies derived Dietary Reference Values (DRVs) for phosphorus. The Panel considered data from balance studies, losses of phosphorus from the body and intestinal absorption for possible use...... countries, which are considerably higher than the values calculated. The AI is 160 mg/day for infants (7–11 months) and between 250 and 640 mg/day for children. For adults, the AI is 550 mg/day. Taking into consideration adaptive changes in phosphorus metabolism that occur during pregnancy and lactation...

Thermal Change for Photovoltaic Panels and Energy Effects

OpenAIRE

İmal, Nazım; Hasar, Şahabettin; Çınar, Harun; Şener, Eralp

2015-01-01

Photovoltaic panels (solar cells), they receive photon energy from sunlight, convert them to electrical energy by the semiconductor structural features. Photovoltaic panels produce a voltage, depending on the change of functional sunlight exposure. Produced voltage and determining of provided electrical power, must be dealt with the physical parameters that uses the concepts of light and temperature. In this study, usage of monocrystalline and polycrystalline structured photovoltaic panels el...

Mounting clips for panel installation

Science.gov (United States)

Cavieres, Andres; Al-Haddad, Tristan; Goodman, Joseph

2017-07-11

A photovoltaic panel mounting clip comprising a base, central indexing tabs, flanges, lateral indexing tabs, and vertical indexing tabs. The mounting clip removably attaches one or more panels to a beam or the like structure, both mechanically and electrically. It provides secure locking of the panels in all directions, while providing guidance in all directions for accurate installation of the panels to the beam or the like structure.

Experimental study of the longitudinal instability for beam transport

International Nuclear Information System (INIS)

Reiser, M.; Wang, J.G.; Guo, W.M.; Wang, D.X.

1990-01-01

Theoretical model for beam longitudinal instability in a transport pipe with general wall impedance is considered. The result shows that a capacitive wall tends to stabilize the beam. The experimental study of the instability for a pure resistive-wall is presented, including the design parameters, setup and components for the experiment. 6 refs., 3 figs

Pilot dynamics for instrument approach tasks: Full panel multiloop and flight director operations

Science.gov (United States)

Weir, D. H.; Mcruer, D. T.

1972-01-01

Measurements and interpretations of single and mutiloop pilot response properties during simulated instrument approach are presented. Pilot subjects flew Category 2-like ILS approaches in a fixed base DC-8 simulaton. A conventional instrument panel and controls were used, with simulated vertical gust and glide slope beam bend forcing functions. Reduced and interpreted pilot describing functions and remmant are given for pitch attitude, flight director, and multiloop (longitudinal) control tasks. The response data are correlated with simultaneously recorded eye scanning statistics, previously reported in NASA CR-1535. The resulting combined response and scanning data and their interpretations provide a basis for validating and extending the theory of manual control displays.

Numerical Study for Compressive Strength of Basalt Composite Sandwich Infill Panel

OpenAIRE

Viriyavudh Sim; Jung Kyu Choi; Yong Ju Kwak; Oh Hyeon Jeon; Woo Young Jung

2017-01-01

In this study, we investigated the buckling performance of basalt fiber reinforced polymer (BFRP) sandwich infill panels. Fiber Reinforced Polymer (FRP) is a major evolution for energy dissipation when used as infill material of frame structure, a basic Polymer Matrix Composite (PMC) infill wall system consists of two FRP laminates surrounding an infill of foam core. Furthermore, this type of component is for retrofitting and strengthening frame structure to withstand the seismic disaster. In...

Procedural justice and prisoners’ mental health problems: A longitudinal study

NARCIS (Netherlands)

Beijersbergen, K.A.; Dirkzwager, A.J.E.; Eichelsheim, V.I.; van der Laan, P.H.; Nieuwbeerta, P.

2013-01-01

Background Given the high prevalence of mental health problems among prisoners, knowledge on its determinants is important. Prior cross-sectional studies suggest that procedurally just treatment within prison is a significant predictor; however, longitudinal research is lacking. Aim The aims of this

Human values and the emergence of a sustainable consumption pattern: A panel study

DEFF Research Database (Denmark)

Thøgersen, John; Ølander, Carl Folke

2002-01-01

In this study, data from a random sample of Danish consumers are used to test the hypothesis that the emergence of a sustainable consumption pattern is influenced by individual value priorities. By the use of a cross-lagged panel design and structural equation modelling it is possible to draw...

Study of the effect of finite extent on sound transmission loss of single panel using a waveguide model

OpenAIRE

Prasetiyo , Iwan; Thompson , David

2012-01-01

International audience; The sound transmission loss (STL) of a panel is often estimated using an infinite plate model. However, some discrepancies are found between these predicted results and experimental ones. One of the sources of such discrepancies corresponds to the finite extent that is naturally found in real structures. In the present study an analytical waveguide model of sound transmission is used to study the effect of finite dimensions in one direction for a panel which is long in...

A Longitudinal Study Assessing the Microsoft Office Skills Course

Science.gov (United States)

Carpenter, Donald A.; McGinnis, Denise; Slauson, Gayla Jo; Snyder, Johnny

2013-01-01

This paper explains a four-year longitudinal study of the assessment process for a Microsoft Office skills course. It examines whether there is an increase in students' knowledge based on responses to pre- and post-surveys that asked students to evaluate how well they can do particular tasks. Classical classroom teaching methods were used in the…

Income Inequality and Gambling: A panel study in the United States (1980-1997)

NARCIS (Netherlands)

Bol, T.; Lancee, B.; Steijn, S.

2014-01-01

While there are many studies that examine the consequences of increasing income inequality, its effects on gambling behavior have not yet been studied. In this article, we argue that income inequality increases the average expenditure on gambling. Using longitudinal state-level data for the United

Air pollution and respiratory health of children: the PEACE panel study in Umea., Sweden.

NARCIS (Netherlands)

Forsberg, B.; Segerstedt, B.; Stjernberg, N.; Roemer, W.

1998-01-01

The Pollution Effects on Asthmatic Children in Europe (PEACE) study examined the acute effects of short-term changes in air pollution on symptomatic children. We were one of 14 research centres in Europe that used a common study protocol. Seventy five children in an urban panel and 72 children in a

Air pollution and respiratory health of children: the PEACE panel study in Krakow., Poland.

NARCIS (Netherlands)

Haluszka, J.; Pisiewics, K.; Miczynski, J.; Roemer, W.; Tomalak, W.

1998-01-01

The Krakow panel study was performed as part of the Pollution Effects on Asthmatic Children in Europe (PEACE) project. The aim of the study was to examine the acute effects of short-term changes in air pollution on symptomatic children. Krakow served as the urban area and Rabka, a small health

Mathematics, Language, and Learning: A Longitudinal Study of Elementary Teachers and Their Mathematics Teaching Practices

OpenAIRE

Yeh, Cathery

2016-01-01

Elementary school mathematics has gained increased attention in the last few decades. A growing field of research has studied the programmatic design and development of elementary mathematics teaching in teacher education, however, few studies have examined longitudinally the mathematics teaching of novice elementary teachers. Existing longitudinal studies on elementary mathematics teaching have generally focused on the effects of teacher preparation on their beginning practices and have exam...

Trajectories of Mental Health over 16 Years amongst Young Adult Women: The Australian Longitudinal Study on Women's Health

Science.gov (United States)

Holden, Libby; Ware, Robert S.; Lee, Christina

2016-01-01

This article used data from 5,171 young women participating in the Australian Longitudinal Study on Women's Health, a nationally representative longitudinal cohort study, to identify longitudinal trajectory patterns of mental health across 6 surveys over 16 years of early adulthood, from age 18-23 to age 34-39. In addition, we identified both…

English as a Foreign Language Spelling Development: A Longitudinal Study

Science.gov (United States)

Kahn-Horwitz, Janina; Sparks, Richard L.; Goldstein, Zahava

2012-01-01

English as a foreign language (EFL) spelling was examined longitudinally three times (4th, 9th, 12th grades) during 9 years of EFL study among Hebrew first language (L1) students. The study examined the impact of L1 literacy variables including phonemic awareness, word attack, and spelling on EFL spelling and the relationship between EFL literacy…

Which emotional regulatory strategy makes Chinese adolescents happier? A longitudinal study.

Science.gov (United States)

Sang, Biao; Deng, Xinmei; Luan, Ziyan

2014-12-01

Growing interest in emotion regulation is reflected in the studies of cognitive and social development. However, the extant studies mainly highlight how emotion regulation develops based on a western value system. This study utilised a longitudinal design to examine the development of emotion regulation and explored the contributions of different regulatory strategies to emotion experience regarding the early adolescent development period in a Chinese population. A total of 303 Chinese adolescents (age range = 10-14 years) were followed up in a three-phase longitudinal study for 3 years. In each phase of the study, participants completed Adolescents Emotion Regulation Questionnaire and Daily Emotion Scale. Results of hierarchical linear regressions revealed that Chinese adolescents reported more down-regulation. Down-regulation is more effective than up-regulation in enhancing desirable emotion experience and reducing undesirable emotion experience during adolescents' development. Also, the adaptive functions of emotional regulatory strategies in Chinese background were discussed. © 2014 International Union of Psychological Science.

Validation of general job satisfaction in the Korean Labor and Income Panel Study.

Science.gov (United States)

Park, Shin Goo; Hwang, Sang Hee

2017-01-01

The purpose of this study is to assess the validity and reliability of general job satisfaction (JS) in the Korean Labor and Income Panel Study (KLIPS). We used the data from the 17th wave (2014) of the nationwide KLIPS, which selected a representative panel sample of Korean households and individuals aged 15 or older residing in urban areas. We included in this study 7679 employed subjects (4529 males and 3150 females). The general JS instrument consisted of five items rated on a scale from 1 (strongly disagree) to 5 (strongly agree). The general JS reliability was assessed using the corrected item-total correlation and Cronbach's alpha coefficient. The validity of general JS was assessed using confirmatory factor analysis (CFA) and Pearson's correlation. The corrected item-total correlations ranged from 0.736 to 0.837. Therefore, no items were removed. Cronbach's alpha for general JS was 0.925, indicating excellent internal consistency. The CFA of the general JS model showed a good fit. Pearson's correlation coefficients for convergent validity showed moderate or strong correlations. The results obtained in our study confirm the validity and reliability of general JS.

Accelerated brain aging in schizophrenia : A longitudinal pattern recognition study

NARCIS (Netherlands)

Schnack, Hugo G.; Van Haren, Neeltje E M; Nieuwenhuis, Mireille; Pol, Hilleke E Hulshoff; Cahn, Wiepke; Kahn, René S.

2016-01-01

OBJECTIVE: Despite the multitude of longitudinal neuroimaging studies that have been published, a basic question on the progressive brain loss in schizophrenia remains unaddressed: Does it reflect accelerated aging of the brain, or is it caused by a fundamentally different process? The authors used

Accelerated Brain Aging in Schizophrenia : A Longitudinal Pattern Recognition Study

NARCIS (Netherlands)

Schnack, Hugo G; van Haren, Neeltje E M; Nieuwenhuis, Mireille; Hulshoff Pol, Hilleke E; Cahn, Wiepke; Kahn, René S

2016-01-01

OBJECTIVE: Despite the multitude of longitudinal neuroimaging studies that have been published, a basic question on the progressive brain loss in schizophrenia remains unaddressed: Does it reflect accelerated aging of the brain, or is it caused by a fundamentally different process? The authors used

Temperature Dependences on Various Types of Photovoltaic (PV) Panel

International Nuclear Information System (INIS)

Audwinto, I A; Leong, C S; Sopian, K; Zaidi, S H

2015-01-01

Temperature is one of the key roles in PV technology performance, since with the increases of temperature the open-circuit voltage will drop accordingly so do the electrical efficiency and power output generation. Different types of Photovoltaic (PV) panels- silicon solar panels and thin film solar panels; mono-crystalline, poly-crystalline, CIS, CIGS, CdTe, back-contact, and bi-facial solar panel under 40°C to 70°C approximately with 5°C interval have been comparatively analyzed their actual performances with uniformly distribution of light illumination from tungsten halogen light source, ±500W/m 2 . DC-Electronic Load and Data Logger devices with “Lab View” data program interface were used to collect all the necessary parameters in this study. Time needed to achieve a certain degree of temperature was recorded. Generally, each of the panels needed 15 minutes to 20 minutes to reach 70°C. Halogen based light source is not compatible in short wave-length in response to thin-film solar cell. Within this period of times, all the panels are facing a performance loss up to 15%. Other parameters; P max , V max , I max , V oc , I sc , R serries , R shunt , Fillfactor were collected as study cases. Our study is important in determining Photovoltaic type selection and system design as for study or industrial needed under different temperature condition. (paper)

A Service Member's Self in Transition : A Longitudinal Case Study Analysis

NARCIS (Netherlands)

Grimell, Jan

2017-01-01

Adopting a narrative approach with a dialogical framework, a longitudinal case study is presented that describes a service member's self in transition from active service into the civilian population. An analysis and interpretation of the case study leads to the hypothesis that if a dominant

Unemployment scarring by gender: Human capital depreciation or stigmatization? Longitudinal evidence from the Netherlands, 1980-2000.

Science.gov (United States)

Mooi-Reci, Irma; Ganzeboom, Harry B

2015-07-01

Using longitudinal data from the Dutch Labor Force Supply Panel (OSA), this article examines how unemployment scarring (i.e., wage setbacks following unemployment) and its underlying mechanisms operate across gender in the Netherlands over the period 1985-2000. A series of fixed effect panel models that correct for unobserved heterogeneity, reveal a notable disparity in unemployment scarring by gender. Interestingly, while unemployment scarring is short-lived and partly conditional upon human capital differences among women, it is strongly persistent among men and contingent upon old age, ethnicity, and tight economic conditions. Our findings provide new evidence regarding unemployment scarring by gender while they support the hypothesis that among women the effects of unemployment scarring are predominantly driven by human capital depreciation, while among men stigma effects dominate. Copyright © 2014 Elsevier Inc. All rights reserved.

Panel Session

DEFF Research Database (Denmark)

Bertelsen, Olav Wedege

2004-01-01

In this panel session, four researchers will discuss the role of a theoretical foundation, in particular AT, in the design of information technology based artefacts. The general discussion will take of from a specific examination of the ActAD approach.......In this panel session, four researchers will discuss the role of a theoretical foundation, in particular AT, in the design of information technology based artefacts. The general discussion will take of from a specific examination of the ActAD approach....

Quantitative study of sniffer leak rate and pressure drop leak rate of liquid nitrogen panels of SST-1 tokamak

Science.gov (United States)

Pathan, F. S.; Khan, Z.; Semwal, P.; Raval, D. C.; Joshi, K. S.; Thankey, P. L.; Dhanani, K. R.

2008-05-01

Steady State Super-conducting (SST-1) Tokamak is in commissioning stage at Institute for Plasma Research. Vacuum chamber of SST-1 Tokamak consists of 1) Vacuum vessel, an ultra high vacuum (UHV) chamber, 2) Cryostat, a high vacuum (HV) chamber. Cryostat encloses the liquid helium cooled super-conducting magnets (TF and PF), which require the thermal radiation protection against room temperature. Liquid nitrogen (LN2) cooled panels are used to provide thermal shield around super-conducting magnets. During operation, LN2 panels will be under pressurized condition and its surrounding (cryostat) will be at high vacuum. Hence, LN2 panels must have very low leak rate. This paper describes an experiment to study the behaviour of the leaks in LN2 panels during sniffer test and pressure drop test using helium gas.

Quantitative study of sniffer leak rate and pressure drop leak rate of liquid nitrogen panels of SST-1 tokamak

Energy Technology Data Exchange (ETDEWEB)

Pathan, F S; Khan, Z; Semwal, P; Raval, D C; Joshi, K S; Thankey, P L; Dhanani, K R [Institute for Plasma Research, Bhat, Gandhinagar - 382 428, Gujarat (India)], E-mail: firose@ipr.res.in

2008-05-01

Steady State Super-conducting (SST-1) Tokamak is in commissioning stage at Institute for Plasma Research. Vacuum chamber of SST-1 Tokamak consists of 1) Vacuum vessel, an ultra high vacuum (UHV) chamber, 2) Cryostat, a high vacuum (HV) chamber. Cryostat encloses the liquid helium cooled super-conducting magnets (TF and PF), which require the thermal radiation protection against room temperature. Liquid nitrogen (LN2) cooled panels are used to provide thermal shield around super-conducting magnets. During operation, LN{sub 2} panels will be under pressurized condition and its surrounding (cryostat) will be at high vacuum. Hence, LN{sub 2} panels must have very low leak rate. This paper describes an experiment to study the behaviour of the leaks in LN{sub 2} panels during sniffer test and pressure drop test using helium gas.

Quantitative study of sniffer leak rate and pressure drop leak rate of liquid nitrogen panels of SST-1 tokamak

International Nuclear Information System (INIS)

Pathan, F S; Khan, Z; Semwal, P; Raval, D C; Joshi, K S; Thankey, P L; Dhanani, K R

2008-01-01

Steady State Super-conducting (SST-1) Tokamak is in commissioning stage at Institute for Plasma Research. Vacuum chamber of SST-1 Tokamak consists of 1) Vacuum vessel, an ultra high vacuum (UHV) chamber, 2) Cryostat, a high vacuum (HV) chamber. Cryostat encloses the liquid helium cooled super-conducting magnets (TF and PF), which require the thermal radiation protection against room temperature. Liquid nitrogen (LN2) cooled panels are used to provide thermal shield around super-conducting magnets. During operation, LN 2 panels will be under pressurized condition and its surrounding (cryostat) will be at high vacuum. Hence, LN 2 panels must have very low leak rate. This paper describes an experiment to study the behaviour of the leaks in LN 2 panels during sniffer test and pressure drop test using helium gas

A longitudinal study of multidimensional performance characteristics related to physical capacities in youth handball.

Science.gov (United States)

Matthys, Stijn P J; Vaeyens, Roel; Fransen, Job; Deprez, Dieter; Pion, Johan; Vandendriessche, Joric; Vandorpe, Barbara; Lenoir, Matthieu; Philippaerts, Renaat

2013-01-01

Longitudinal research provides valuable information about change and progress towards elite performance. Unfortunately, there is a lack of longitudinal research in handball. In this study, 94 youth handball players (oldest group: n = 41; age 15-17 and youngest group: n = 53; age 13-15) were followed over a three-year period. Repeated measures ANCOVA was conducted to reveal longitudinal changes in anthropometry and physical performance between elite and non-elite players, controlling for maturation. Maturation effects were found for anthropometry (P team handball should recognise the importance of good skills and an excellent endurance for talent identification purposes.

Studies of cryocooler based cryosorption pump with activated carbon panels operating at 11K

International Nuclear Information System (INIS)

Kasthurirengan, S; Behera, Upendra; Gangradey, Ranjana; Udgata, Swarup; Krishnamoorthy, V

2012-01-01

Cryosorption pump is the only solution for pumping helium and hydrogen in fusion reactors. It is chosen because it offers highest pumping speed as well as the only suitable pump for the harsh environments in a tokamak. Towards the development of such cryosorption pumps, the optimal choice of the right activated carbon panels is essential. In order to characterize the performance of the panels with indigenously developed activated carbon, a cryocooler based cryosorption pump with scaled down sizes of panels is experimented. The results are compared with the commercial cryopanel used in a CTI cryosorption (model: Cryotorr 7) pump. The cryopanel is mounted on the cold head of the second stage GM cryocooler which cools the cryopanel down to 11K with first stage reaching about ∼50K. With no heat load, cryopump gives the ultimate vacuum of 2.1E-7 mbar. The pumping speed of different gases such as nitrogen, argon, hydrogen, helium are tested both on indigenous and commercial cryopanel. These studies serve as a bench mark towards the development of better cryopanels to be cooled by liquid helium for use with tokamak.

Compressive strength of thick composite panels

DEFF Research Database (Denmark)

Branner, Kim; Berring, Peter

2011-01-01

The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used in the structu......The aim of this study is to investigate how much the compressive strength of thick composite panels is reduced due to delaminations and to investigate under which conditions a delamination will grow. Understanding of this is essential in order to move forward the design limits used...

78 FR 41937 - Joint Meeting of the Gastroenterology-Urology Panel and the Radiological Devices Panel of the...

Science.gov (United States)

2013-07-12

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0816] Joint Meeting of the Gastroenterology-Urology Panel and the Radiological Devices Panel of the Medical...: Gastroenterology-Urology Panel and Radiological Devices Panel of the Medical Devices Advisory Committee. General...

Longitudinal Study of the Market Penetration of Cockpit Weather Information Systems

Science.gov (United States)

Stough, Harry Paul, III; Sireli, Yesim; Ozan, Erol; Kauffmann, Paul

2005-01-01

The purpose of the longitudinal research of the market penetration of cockpit weather information systems (CWIS) is to contribute to the body of knowledge on modeling advanced technology feasibility in aviation by tracking and analyzing the market adoption of CWIS over a three year period. This research takes advantage of a previous study, conducted by Dr. Paul Kauffmann in 2000, which demonstrated an integrated and cost effective approach to evaluate advanced technology feasibility, examining the feasibility of CWIS in five market segments: transport, commuter, general aviation, business, and rotorcraft. The longitudinal research consists of two consecutive studies and produced two reports. The first report was submitted in August 2003 and included general market analysis about the CWIS products in the market at the time, identified their characteristics and examined developing market dynamics.

Improvement of road noise by reduction of acoustic radiation from body panels; Panel no hoshaon teigen ni yoru road noise no kaizen

Energy Technology Data Exchange (ETDEWEB)

Kamura, T; Utsunomiya, A; Sugihara, T; Tobita, K [Mazda Motor Corp., Hiroshima (Japan)

1997-10-01

This paper describes road noise reduction methods accomplished by reducing acoustic power radiated from body panels. Fundamental study of acoustic and dynamic characteristics with rectangular panels revealed following results: (1) The lower stiffness panel had lower radiation efficiency and made damping materials work more effective to reduce the acoustic power. (2) The acoustic power was also reduced by designing the panel so that it can generate the vibration of (2, 2) mode, which has the lowest radiation efficiency, in road noise frequency region. By applying these methods to a vehicle floor, we confirmed the improvement of road noise performance. 3 refs., 12 figs.

[A school-level longitudinal study of clinical performance examination scores].

Science.gov (United States)

Park, Jang Hee

2015-06-01

This school-level longitudinal study examined 7 years of clinical performance data to determine differences (effects) in students and annual changes within a school and between schools; examine how much their predictors (characteristics) influenced the variation in student performance; and calculate estimates of the schools' initial status and growth. A school-level longitudinal model was tested: level 1 (between students), level 2 (annual change within a school), and level 3 (between schools). The study sample comprised students who belonged to the CPX Consortium (n=5,283 for 2005~2008 and n=4,337 for 2009~2011). Despite a difference between evaluation domains, the performance outcomes were related to individual large-effect differences and small-effect school-level differences. Physical examination, clinical courtesy, and patient education were strongly influenced by the school effect, whereas patient-physician interaction was not affected much. Student scores are influenced by the school effect (differences), and the predictors explain the variation in differences, depending on the evaluation domain.

Stages of Headship: A Longitudinal Study of the Principalship.

Science.gov (United States)

Weindling, Dick

This paper uses socialization theory to re-examine a unique, 10-year longitudinal study of headteachers so as to describe the stages of headship transition. It outlines prior models of leadership succession in both business and schools and produces a stage theory of headship that can be used not only as a research tool, but also as a way to assist…

Longitudinal population-based studies of affective disorders: Where to from here?

Directory of Open Access Journals (Sweden)

Beard John R

2008-09-01

Full Text Available Abstract Background Longitudinal, population-based, research is important if we are to better characterize the lifetime patterns and determinants of affective disorders. While studies of this type are becoming increasingly prevalent, there has been little discussion about the limitations of the methods commonly used. Methods Discussion paper including a brief review of key prospective population-based studies as the basis for a critical appraisal of current approaches. Results We identified a number of common methodological weaknesses that restrict the potential of longitudinal research to characterize the diversity, prognosis, and determinants of affective disorders over time. Most studies using comprehensive diagnostic instruments have either been of relatively brief duration, or have suffered from long periods between waves. Most etiologic research has focused on first onset diagnoses, although these may be relatively uncommon after early adulthood and the burden of mental disorders falls more heavily on individuals with recurring disorders. Analysis has tended to be based on changes in diagnostic status rather than anges in symptom levels, limiting study power. Diagnoses have generally been treated as homogeneous entities and few studies have explored whether diagnostic subtypes such as atypical depression vary in their etiology or prognosis. Little research has considered whether there are distinct trajectories of symptoms over time and most has focused on individual disorders such as depression, rather than considering the relationship over time between symptoms of different affective disorders. There has also been limited longitudinal research on factors in the physical or social environment that may influence the onset, recurrence or chronicity of symptoms. Conclusion Many important, and in some respects quite basic, questions remain about the trajectory of depression and anxiety disorders over the life course and the factors that

Precast concrete sandwich panels subjected to impact loading

Science.gov (United States)

Runge, Matthew W.

Precast concrete sandwich panels are a relatively new product in the construction industry. The design of these panels incorporates properties that allow for great resilience against temperature fluctuation as well as the very rapid and precise construction of facilities. The concrete sandwich panels investigated in this study represent the second generation of an ongoing research and development project. This second generation of panels have been engineered to construct midsized commercial buildings up to three stories in height as well as residential dwellings. The panels consist of a double-tee structural wythe, a foam core and a fascia wythe, joined by shear connectors. Structures constructed from these panels may be subjected to extreme loading including the effects of seismic and blast loading in addition to wind. The aim of this work was to investigate the behaviour of this particular sandwich panel when subjected to structural impact events. The experimental program consisted of fourteen concrete sandwich panels, five of which were considered full-sized specimens (2700 mm X 1200mm X 270 mm) and nine half-sized specimens (2700mm X 600mm X 270 mm) The panels were subjected to impact loads from a pendulum impact hammer where the total energy applied to the panels was varied by changing the mass of the hammer. The applied loads, displacements, accelerations, and strains at the mid-span of the panel as well as the reaction point forces were monitored during the impact. The behaviour of the panels was determined primarily from the experimental results. The applied loads at low energy levels that caused little to no residual deflection as well as the applied loads at high energy levels that represent catastrophic events and thus caused immediate failure were determined from an impact on the structural and the fascia wythes. Applied loads at intermediate energy levels representing extreme events were also used to determine whether or not the panels could withstand

Postural changes in dental hygienists. Four-year longitudinal study.

Science.gov (United States)

Barry, R M; Woodall, W R; Mahan, J M

1992-01-01

Numerous surveys identify the occurrence of musculoskeletal complaints as a concern in dentistry. However, no longitudinal data exist to indicate whether postural changes occur as a result of practicing dental hygiene. The purpose of this preliminary, four-year longitudinal study was to investigate whether any postural changes developed during the hygienists' clinical education and/or during subsequent dental hygiene practice after one and/or two years. It was anticipated that the awkward positions and intense physical demands placed on hygienists might initiate musculoskeletal problems, but that no postural changes would occur over this short period of time. Nine of 10 dental hygienists in the graduating class of 1987 were surveyed for existing musculoskeletal complaints, and the subjects were photographed for a measurement of postural change. Responses from participants indicated an increase in musculoskeletal-related complaints in each of the six areas investigated. The photographic findings indicated that one of the nine hygienists showed an increase in forward head posture, a postural change.

Reckoning HIV/AIDS care: A longitudinal study of community home ...

African Journals Online (AJOL)

To better understand the potential significance of global and national health policy/programming reliance on community health workers (task shifting), we analysed longitudinal data on both care supporter and client cohorts from 2008 to 2013. Most CHBC studies report data from only one cohort. Foremost, our analysis ...

Brief report: parenting styles and obesity in Mexican American children: a longitudinal study.

Science.gov (United States)

Olvera, Norma; Power, Thomas G

2010-04-01

To assess longitudinally the relations between four parenting styles (authoritative, authoritarian, uninvolved, and indulgent) and child weight status in Mexican American families. Sixty-nine low-income Mexican American mothers and their 4- to 8-year-old children participated in a 4-year longitudinal study. Mothers completed demographic and parenting measures. Children's body weight and height were assessed annually. Body mass index was calculated to determine weight status. At baseline, 65% of children were found to be normal weight, 14% were overweight, and 21% were obese. Analyses examined how parenting styles at baseline predicted child's weight status 3 years later, controlling for initial weight status. Children of indulgent mothers were more likely to become overweight 3 years later than children of authoritative or authoritarian mothers. This study provides longitudinal evidence for the role of indulgent parenting in predicting overweight in Mexican American children. Possible mediating factors that may account for this relationship (e.g., dietary patterns, physical activity patterns, and children's self-regulation) are considered.

A Longitudinal Study of the Determinants and Outcomes of Career Change

Science.gov (United States)

Carless, Sally A.; Arnup, Jessica L.

2011-01-01

The present longitudinal field study investigated the antecedents and consequences of an actual career change. The framework for this study was Rhodes and Doering's (1983) model of career change. We examined the effect of individual and organisational characteristics on career change behaviour. The individual characteristics were: traits (Openness…

Longitudinal Study of Body Mass Index in Young Males and the Transition to Fatherhood.

Science.gov (United States)

Garfield, Craig F; Duncan, Greg; Gutina, Anna; Rutsohn, Joshua; McDade, Thomas W; Adam, Emma K; Coley, Rebekah Levine; Chase-Lansdale, P Lindsay

2016-11-01

Despite a growing understanding that the social determinants of health have an impact on body mass index (BMI), the role of fatherhood on young men's BMI is understudied. This longitudinal study examines BMI in young men over time as they transition from adolescence into fatherhood in a nationally representative sample. Data from all four waves of the National Longitudinal Study of Adolescent Health supported a 20-year longitudinal analysis of 10,253 men beginning in 1994. A "fatherhood-year" data set was created and changes in BMI were examined based on fatherhood status (nonfather, nonresident father, resident father), fatherhood years, and covariates. Though age is positively associated with BMI over all years for all men, comparing nonresident and resident fathers with nonfathers reveals different trajectories based on fatherhood status. Entrance into fatherhood is associated with an increase in BMI trajectory for both nonresident and resident fathers, while nonfathers exhibit a decrease over the same period. In this longitudinal, population-based study, fatherhood and residence status play a role in men's BMI. Designing obesity prevention interventions for young men that begin in adolescence and carry through young adulthood should target the distinctive needs of these populations, potentially improving their health outcomes. © The Author(s) 2015.

Micro-inverter solar panel mounting

Science.gov (United States)

Morris, John; Gilchrist, Phillip Charles

2016-02-02

Processes, systems, devices, and articles of manufacture are provided. Each may include adapting micro-inverters initially configured for frame-mounting to mounting on a frameless solar panel. This securement may include using an adaptive clamp or several adaptive clamps secured to a micro-inverter or its components, and using compressive forces applied directly to the solar panel to secure the adaptive clamp and the components to the solar panel. The clamps can also include compressive spacers and safeties for managing the compressive forces exerted on the solar panels. Friction zones may also be used for managing slipping between the clamp and the solar panel during or after installation. Adjustments to the clamps may be carried out through various means and by changing the physical size of the clamps themselves.

1994 Panel 1 Utilization Plan

International Nuclear Information System (INIS)

1994-01-01

The Waste Isolation Pilot Plant (WIPP) is intended to receive, handle, and permanently dispose of transuranic (TRU) waste. To fulfill this mission, the U.S. Department of Energy (DOE) constructed a full-scale facility to demonstrate both technical and operational principles of the permanent isolation of TRU waste. The WIPP consists of surface and underground facilities. Panel 1 is situated in the underground facility horizon which is located approximately 2,150 feet below the surface in the predominantly halite Salado Formation. The Panel 1 Utilization Plan provides a strategy for the optimum use of Panel 1 which is consistent with the priorities established by the DOE to accomplish the WIPP mission. These priorities, which include maintaining personnel safety, conducting performance assessment, and continued operational enhancements, are the guiding premise for the decisions on the planned usage of the WIPP underground facility. The continuation of ongoing investigations along with the planned testing and training to be carried out in Panel 1 will enhance the current knowledge and understanding of the operational and geotechnical aspects of the panel configuration. This enhancement will ultimately lead to safer, more efficient, and more cost-effective methods of operation. Excavation of the waste storage area began in May 1986 with the mining of entries to Panel 1. The original design for the waste storage rooms at the WIPP provided a limited period of time during which to mine the openings and to emplace waste. Each panel, consisting of seven storage rooms, was scheduled to be mined and filled in less than 5 years. Panel 1 was developed to receive waste for a demonstration phase that was scheduled to start in October 1988. The demonstration phase was deferred, and the experimental test program was modified to use contact-handled (CH) transuranic waste in bin-scale tests, planned for Room 1, Panel 1

Screening life cycle assessment study of a sisal fibre reinforced micro-concrete structural insulated panel

CSIR Research Space (South Africa)

Ampofo-Anti, N

2013-12-01

Full Text Available First international conference on composites, biocomposites and nanocomposites, DUT, Durban, South Africa, 2-4 December 2013 SCREENING LIFE CYCLE ASSESSMENT STUDY OFA SISAL FIBRE REINFORCED MICRO-CONCRETE STRUCTURAL INSULATED PANEL Naa Lamkai Ampofo...

Potential Reciprocal Relationship between Motivation and Achievement: A Longitudinal Study

Science.gov (United States)

Liu, Yuan; Hou, Shumeng

2018-01-01

Among the non-cognitive factors that influence academic achievement, intrinsic motivation has been found to be a potential reciprocal factor. The present study aims to determine the causal relationship between other types of motivation and academic achievement. For this purpose, a large-scale data survey, the National Education Longitudinal Study…

Data quality in probability-based online panels: Nonresponse, attrition, and panel conditioning

NARCIS (Netherlands)

Struminskaya, B.; Methodology and statistics for the behavioural and social sciences

2014-01-01

Online panels – surveys administered over the Internet in which persons are asked to complete surveys regularly – offer cost reductions compared to surveys that use more traditional modes of data collection (face-to-face, telephone, and mail). However, some characteristics of online panels may cause

Causas de los accidentes de trabajo en España: análisis longitudinal con datos de panel Causes of occupational injuries in Spain: a longitudinal analysis with panel data

Directory of Open Access Journals (Sweden)

Inmaculada García Mainar

2009-06-01

Full Text Available Objetivos: Se pretende investigar la influencia de algunas características, tanto de los trabajadores como de los puestos de trabajo que ocupan, en la incidencia de accidentes laborales por categorías (leves, graves, mortales y totales, utilizando herramientas propias del análisis económico. Métodos: Se utiliza un panel de datos para estimar los determinantes de los accidentes agregados de dos formas: por comunidades autónomas y ocupación, y por ramas de actividad y ocupación. Los datos de los accidentes provienen del Ministerio de Trabajo y Asuntos Sociales, y el resto de la Encuesta de Población Activa, para todos los trimestres desde 1999 hasta 2002. Resultados: Un mayor porcentaje de trabajadores con contrato indefinido, del sector público, con estudios secundarios o que han recibido cursos de formación, se asocia con una menor incidencia de accidentes, mientras que una mayor proporción de varones o extranjeros se relaciona con una mayor incidencia. Una mayor experiencia laboral reduce el riesgo de accidente grave o mortal, mientras que más horas de trabajo lo aumentan. Conclusiones: Sería recomendable una mayor actuación para reducir el riesgo de accidente en los trabajadores temporales, los que trabajan en el sector privado, los varones y los extranjeros. Para reducir la incidencia de los accidentes mortales, habría que limitar además el número de horas trabajadas, especialmente en los casos en que no se cuente con una amplia experiencia laboral.Objectives: To investigate the influence of several personal and occupational characteristics on the occurrence of occupation injuries, expressed in different categories (minor, serious, fatal and overall by applying tools that are widely used in economic analyses. Methods: Panel data were used to estimate occupational injuries in an aggregate manner: both by regions and occupational categories and by industries and occupational categories. Data on occupational injuries were drawn

Work-to-family conflict and its relationship with satisfaction and well-being: A one-year longitudinal study

NARCIS (Netherlands)

Kinnunen, U.; Geurts, S.A.E.; Mauno, S.

2004-01-01

The present study produced new knowledge about gender differences with respect to work-to-family conflict and its longitudinal relations with indicators of satisfaction and well-being. The study examined the longitudinal relations between work-to-family conflict and self-reported satisfaction and

High School Longitudinal Study of 2009 (HSLS:09): Base-Year Data File Documentation. NCES 2011-328

Science.gov (United States)

Ingels, Steven J.; Pratt, Daniel J.; Herget, Deborah R.; Burns, Laura J.; Dever, Jill A.; Ottem, Randolph; Rogers, James E.; Jin, Ying; Leinwand, Steve

2011-01-01

The High School Longitudinal Study of 2009 (HSLS:09) is the fifth in a series of National Center for Education Statistics (NCES) secondary longitudinal studies. The core research questions for HSLS:09 explore secondary to postsecondary transition plans and the evolution of those plans; the paths into and out of science, technology, engineering,…

Behavior of Frame-Stiffened Composite Panels with Damage

Science.gov (United States)

Jegley, Dawn C.

2013-01-01

NASA, the Air Force Research Laboratory and The Boeing Company have worked to develop new low-cost, light-weight composite structures for aircraft. A Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept has been developed which offers advantages over traditional metallic structures. In this concept, a stitched carbon-epoxy material system has been developed with the potential for reducing the weight and cost of transport aircraft structure by eliminating fasteners, thereby reducing part count and labor. Stitching and the use of thin skins with rod-stiffeners to move loading away from the morevulnerable outer surface produces a structurally efficient, damage tolerant design. This study focuses on the behavior of PRSEUS panels loaded in the frame direction and subjected to severe damage in the form of a severed central frame in a three-frame panel. Experimental results for a pristine two-frame panel and analytical predictions for pristine two-frame and three-frame panels as well as damaged three-frame panels are described.

Theoretical prediction on corrugated sandwich panels under bending loads

Science.gov (United States)

Shu, Chengfu; Hou, Shujuan

2018-05-01

In this paper, an aluminum corrugated sandwich panel with triangular core under bending loads was investigated. Firstly, the equivalent material parameters of the triangular corrugated core layer, which could be considered as an orthotropic panel, were obtained by using Castigliano's theorem and equivalent homogeneous model. Secondly, contributions of the corrugated core layer and two face panels were both considered to compute the equivalent material parameters of the whole structure through the classical lamination theory, and these equivalent material parameters were compared with finite element analysis solutions. Then, based on the Mindlin orthotropic plate theory, this study obtain the closed-form solutions of the displacement for a corrugated sandwich panel under bending loads in specified boundary conditions, and parameters study and comparison by the finite element method were executed simultaneously.

Resolution of neurosensory deficit after mandibular orthognathic surgery: A prospective longitudinal study.

Science.gov (United States)

Alolayan, Albraa Badr; Leung, Yiu Yan

2017-05-01

To investigate the longitudinal resolution of neurosensory deficit (NSD) and the possible risk factors that might contribute to NSD following mandibular orthognathic procedures. A prospective longitudinal observational study on patients who had mandibular orthognathic procedures was performed. Standardized neurosensory assessments were performed. The 2 years longitudinal resolution and risk factors of NSD including patients' age and gender, specific mandibular procedures and surgeons' experience were analyzed. 66 patients (44 females) with 132 sides of mandibular procedures were enrolled in the study. Surgical procedures included mandibular ramus surgery, anterior mandibular surgery, or the combination of the two. The overall occurrences of subjective NSD improved from 78.8% at postoperative 2 weeks to 13.8% at post-operative 2 years. Combinations of ramus surgery and anterior mandibular surgery increased the risk of NSD at the first three post-operative months (p orthognathic surgery. The occurrence of NSD after mandibular orthognathic procedures reduced progressively within the post-operative 2 years. Combination of mandibular ramus surgery and anterior mandibular surgery increased the risk of NSD in the early post-operative period. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Solar panel truss mounting systems and methods

Energy Technology Data Exchange (ETDEWEB)

Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

2016-06-28

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

Solar panel truss mounting systems and methods

Energy Technology Data Exchange (ETDEWEB)

Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

2018-01-30

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

Solar panel truss mounting systems and methods

Science.gov (United States)

Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

2015-10-20

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

Diet assessment in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil: Development of a food frequency questionnaire

Directory of Open Access Journals (Sweden)

Maria del Carmen Bisi Molina

2013-04-01

Full Text Available OBJECTIVE: The objective of this article is to present the development of the Food Frequency Questionaire used in the Longitudinal Study of Adult Health-Brazil and analyze how diet exposes individuals to cardiovascular diseases and type 2 diabetes Mellitus. METHODS: The Longitudinal Study of Adult Health-Brazil dietary assessment instrument is based on a previously validated Food Frequency Questionaire and the final list of items took into consideration a study done in the six Longitudinal Study of Adult Health-Brazil investigation centers. RESULTS: New foods/preparations were included in the Food Frequency Questionaire with their respective portions, totaling 114 items. The perspectives of dietary analysis and cardiovascular diseases and diabetes are presented in Longitudinal Study of Adult Health-Brazil. CONCLUSION: A new instrument was developed to cover the regional particularities of the study population.

Psychosocial Quality-of-Life, Lifestyle and Adiposity: A Longitudinal Study in Pre-schoolers (Ballabeina Study).

Science.gov (United States)

Michels, Nathalie; Susi, Kriemler; Marques-Vidal, Pedro M; Nydegger, Andreas; Puder, Jardena J

2016-06-01

In obesity prevention, understanding psychosocial influences in early life is pivotal. Reviews reported contradictory results and a lack of longitudinal studies focusing on underlying lifestyle factors. This study tested whether psychosocial Quality-Of-Life (QOL) was associated with pre-schoolers' lifestyle and adiposity changes over one school year and whether lifestyle moderated the latter. It was hypothesised that QOL might not impact adiposity in everybody but that this might depend on preceding lifestyle. Longitudinal data from 291 Swiss pre-schoolers (initially 3.9-6.3 years) was available. The following measures were used in longitudinal regressions: psychosocial QOL by PedsQL, adiposity (BMI z-score, waist, fat%), diet (food frequency), sedentary time and accelerometer-based activity. Concerning lifestyle, low psychosocial QOL was only related to unfavourable changes in diet (less fruit β = 0.21 and more fat intake β = -0.28) and lower physical activity (β = 0.21). Longitudinal QOL-adiposity relations appeared only after moderation by lifestyle factors (beta-range 0.13-0.67). Low psychosocial QOL was associated with increased adiposity in children with an unhealthy diet intake or high sedentary time. By contrast, low psychosocial QOL was associated with decreasing adiposity in high fruit consumers or more physically active pre-schoolers. Results emphasise the need for testing moderation in the QOL-adiposity relation. An unhealthy diet can be a vulnerability factor and high physical activity a protective factor in QOL-related adiposity. Consequently, QOL and lifestyle should be targeted concurrently in multi-factorial obesity prevention. The environment should be an 'activity encouraging, healthy food zone' that minimises opportunities for stress-induced eating. In addition, appropriate stress coping skills should be acquired.

FPGA Implementation of Multilayer Perceptron for Modeling of Photovoltaic panel

International Nuclear Information System (INIS)

Mekki, H.; Belhout, K.; Mellit, A.; Salhi, H.

2008-01-01

The Number of electronic applications using artificial neural network-based solutions has increased considerably in the last few years. However, their applications in photovoltaic systems are very limited. This paper introduces the preliminary result of the modeling and simulation of photovoltaic panel based on neural network and VHDL-language. In fact, an experimental database of meteorological data (irradiation, temperature) and output electrical generation signals of the PV-panel (current and voltage) has been used in this study. The inputs of the ANN-PV-panel are the daily total irradiation and mean average temperature while the outputs are the current and voltage generated from the panel. Firstly, a dataset of 4x364 have been used for training the network. Subsequently, the neural network (MLP) corresponding to PV-panel is simulated using VHDL language based on the saved weights and bias of the network. Simulation results of the trained MLP-PV panel based on Matlab and VHDL are presented. The proposed PV-panel model based ANN and VHDL permit to evaluate the performance PV-panel using only the environmental factors and involves less computational efforts, and it can be used for predicting the output electrical energy from the PV-panel

Graphite/epoxy orthogrid panel fabrication

Science.gov (United States)

Lager, J. R.

1978-01-01

The structural concept considered for a spacecraft body structure is a grid stiffened skin with a skin laminate configuration and the stiffener grid geometry selected to best suit the design requirements. The orthogrid panel developed weighs 0.55 lb/sq ft and resisted an ultimate in-plane shear load of 545 lbf/in. The basic concept of a grid stiffener composite panel is that a relatively thin skin is reinforced with a gridwork of stiffeners so that the overall panel can resist design loads without becoming structurally unstable or being overstressed. The main feature of the orthogrid panel design is that it provides the potential for low cost structural panels when advanced to the production phase. The most innovative part of the fabrication method is the foam/fiberglass stiffener web grid billet fabrication and machining to size.

OPTIMASI SUDUT KEMIRINGAN PANEL SURYA PADA PROTOTIPE SISTEM PENJEJAK MATAHARI AKTIF

OpenAIRE

Tamimi, S.; Indrasari, W.; Iswanto, B. H.

2016-01-01

The main problem on solar energy is instability power which generated by the solar panels, because it depends on the sunlight intensity which accepted by the solar panels. The intensity of sunlight received by the solar panels can be maximized by installing solar panels with a right angle so it will be obtained the maximum output power. This study has been carried out optimization angle of the solar panels that will be used on the active prototype solar tracking system. The optimization is ta...

Assessing type I error and power of multistate Markov models for panel data-A simulation study.

Science.gov (United States)

Cassarly, Christy; Martin, Renee' H; Chimowitz, Marc; Peña, Edsel A; Ramakrishnan, Viswanathan; Palesch, Yuko Y

2017-01-01

Ordinal outcomes collected at multiple follow-up visits are common in clinical trials. Sometimes, one visit is chosen for the primary analysis and the scale is dichotomized amounting to loss of information. Multistate Markov models describe how a process moves between states over time. Here, simulation studies are performed to investigate the type I error and power characteristics of multistate Markov models for panel data with limited non-adjacent state transitions. The results suggest that the multistate Markov models preserve the type I error and adequate power is achieved with modest sample sizes for panel data with limited non-adjacent state transitions.

Optimization of composite sandwich cover panels subjected to compressive loadings

Science.gov (United States)

Cruz, Juan R.

1991-01-01

An analysis and design method is presented for the design of composite sandwich cover panels that include the transverse shear effects and damage tolerance considerations. This method is incorporated into a sandwich optimization computer program entitled SANDOP. As a demonstration of its capabilities, SANDOP is used in the present study to design optimized composite sandwich cover panels for for transport aircraft wing applications. The results of this design study indicate that optimized composite sandwich cover panels have approximately the same structural efficiency as stiffened composite cover panels designed to satisfy individual constraints. The results also indicate that inplane stiffness requirements have a large effect on the weight of these composite sandwich cover panels at higher load levels. Increasing the maximum allowable strain and the upper percentage limit of the 0 degree and +/- 45 degree plies can yield significant weight savings. The results show that the structural efficiency of these optimized composite sandwich cover panels is relatively insensitive to changes in core density. Thus, core density should be chosen by criteria other than minimum weight (e.g., damage tolerance, ease of manufacture, etc.).

Criminal Victimization and Crime Risk Perception: A Multilevel Longitudinal Study

Science.gov (United States)

Russo, Silvia; Roccato, Michele; Vieno, Alessio

2013-01-01

In a national sample of the Italian population, surveyed four times between October 2002 and January 2007 (N = 2,008), we performed a multilevel longitudinal study aimed at predicting the increase in crime risk perception as a function of three families of independent variables, respectively lying at the within individual level (direct…

Minor Delinquency and Immigration: A Longitudinal Study among Male Adolescents

Science.gov (United States)

Titzmann, Peter F.; Silbereisen, Rainer K.; Mesch, Gustavo

2014-01-01

On the basis of general theories of delinquency and the specific situation of immigrants, this longitudinal study investigated predictors of initial levels and rates of change in delinquency among 188 male ethnic German Diaspora immigrants from the former Soviet Union (FSU) in Germany, 237 male native German adolescents, and 182 male Jewish…

Longitudinal Study on Reciprocity between Personality Traits and Parenting Stress

Science.gov (United States)

Rantanen, Johanna; Tillemann, Kati; Metsäpelto, Riitta-Leena; Kokko, Katja; Pulkkinen, Lea

2015-01-01

Reciprocal associations between the Big Five personality traits and parenting stress--including both parents' feelings of their distress and perception of their incompetence as parents--were studied with 248 participants (49% of which were males). Longitudinal data, collected at ages 33/36, 42 and 50 years, were used. Cross-lagged path analysis…

A panel study of migration, self-selection and household real income.

Science.gov (United States)

Axelsson, R; Westerlund, O

1998-02-01

"The impact of migration on income for Swedish multi-adult households is examined using panel data pertaining to a sample of stable household constellations during the period 1980-1990. In contrast to previous studies, data on household disposable income is employed in estimating the income function. The empirical results indicate no significant effect on real disposable income from migration. In addition, the hypothesis of no self-selection, or zero correlation between the errors in the decision function and the income function, cannot be rejected." excerpt

Acoustically Tailored Composite Rotorcraft Fuselage Panels

Science.gov (United States)

Hambric, Stephen; Shepherd, Micah; Koudela, Kevin; Wess, Denis; Snider, Royce; May, Carl; Kendrick, Phil; Lee, Edward; Cai, Liang-Wu

2015-01-01

A rotorcraft roof sandwich panel has been redesigned to optimize sound power transmission loss (TL) and minimize structure-borne sound for frequencies between 1 and 4 kHz where gear meshing noise from the transmission has the most impact on speech intelligibility. The roof section, framed by a grid of ribs, was originally constructed of a single honeycomb core/composite face sheet panel. The original panel has coincidence frequencies near 700 Hz, leading to poor TL across the frequency range of 1 to 4 kHz. To quiet the panel, the cross section was split into two thinner sandwich subpanels separated by an air gap. The air gap was sized to target the fundamental mass-spring-mass resonance of the double panel system to less than 500 Hz. The panels were designed to withstand structural loading from normal rotorcraft operation, as well as 'man-on-the-roof' static loads experienced during maintenance operations. Thin layers of VHB 9469 viscoelastomer from 3M were also included in the face sheet ply layups, increasing panel damping loss factors from about 0.01 to 0.05. Measurements in the NASA SALT facility show the optimized panel provides 6-11 dB of acoustic transmission loss improvement, and 6-15 dB of structure-borne sound reduction at critical rotorcraft transmission tonal frequencies. Analytic panel TL theory simulates the measured performance quite well. Detailed finite element/boundary element modeling of the baseline panel simulates TL slightly more accurately, and also simulates structure-borne sound well.

Sports participation and psychosocial health : a longitudinal observational study in children

NARCIS (Netherlands)

Moeijes, Janet; van Busschbach, Jooske T; Bosscher, Ruud J; Twisk, Jos W R

2018-01-01

BACKGROUND: It is well known that sports participation is positively associated with psychosocial health in children, but details about this association over time are lacking. This study aimed to explore longitudinal associations between several characteristics of sports participation and three

Paneling architectural freeform surfaces

KAUST Repository

Eigensatz, Michael; Kilian, Martin; Schiftner, Alexander; Mitra, Niloy J.; Pottmann, Helmut; Pauly, Mark

2010-01-01

with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication

Prospective, longitudinal, multi-modal functional imaging for radical chemo-IMRT treatment of locally advanced head and neck cancer: the INSIGHT study

International Nuclear Information System (INIS)

Welsh, Liam; Panek, Rafal; McQuaid, Dualta; Dunlop, Alex; Schmidt, Maria; Riddell, Angela; Koh, Dow-Mu; Doran, Simon; Murray, Iain; Du, Yong; Chua, Sue; Hansen, Vibeke; Wong, Kee H.; Dean, Jamie; Gulliford, Sarah; Bhide, Shreerang; Leach, Martin O.; Nutting, Christopher; Harrington, Kevin; Newbold, Kate

2015-01-01

Radical chemo-radiotherapy (CRT) is an effective organ-sparing treatment option for patients with locally advanced head and neck cancer (LAHNC). Despite advances in treatment for LAHNC, a significant minority of these patients continue to fail to achieve complete response with standard CRT. By constructing a multi-modality functional imaging (FI) predictive biomarker for CRT outcome for patients with LAHNC we hope to be able to reliably identify those patients at high risk of failing standard CRT. Such a biomarker would in future enable CRT to be tailored to the specific biological characteristics of each patients’ tumour, potentially leading to improved treatment outcomes. The INSIGHT study is a single-centre, prospective, longitudinal multi-modality imaging study using functional MRI and FDG-PET/CT for patients with LAHNC squamous cell carcinomas receiving radical CRT. Two cohorts of patients are being recruited: one treated with, and another treated without, induction chemotherapy. All patients receive radical intensity modulated radiotherapy with concurrent chemotherapy. Patients undergo functional imaging before, during and 3 months after completion of radiotherapy, as well as at the time of relapse, should that occur within the first two years after treatment. Serum samples are collected from patients at the same time points as the FI scans for analysis of a panel of serum markers of tumour hypoxia. The primary aim of the INSIGHT study is to acquire a prospective multi-parametric longitudinal data set comprising functional MRI, FDG PET/CT, and serum biomarker data from patients with LAHNC undergoing primary radical CRT. This data set will be used to construct a predictive imaging biomarker for outcome after CRT for LAHNC. This predictive imaging biomarker will be used in future studies of functional imaging based treatment stratification for patients with LAHNC. Additional objectives are: defining the reproducibility of FI parameters; determining robust

Evidence of Big-Five personality changes following acquired brain injury from a prospective longitudinal investigation.

Science.gov (United States)

Leonhardt, Anne; Schmukle, Stefan C; Exner, Cornelia

2016-03-01

Many studies using different assessment methods have reported personality changes after acquired brain injury (ABI). However, to our knowledge, no prospective study has yet been conducted to examine whether previous cross-sectional and retrospective results can be replicated in a longitudinal prospective design. Further, because clinical control groups were only rarely used, it remains debatable if the personality changes found are unique to patients with ABI or if they also affect patients with other disabilities. This study examined personality change in 114 participants with different kinds of ABI, 1321 matched controls (general control, GC), and 746 matched participants with restrictive impairments other than brain injury (clinical control, CC) in a prospective longitudinal design using data from the panel survey Household, Income and Labour Dynamics in Australia (HILDA). Participants with ABI showed significantly larger declines in Extraversion and Conscientiousness compared with the GC group. When the ABI participants were compared with the CC group, only the difference in Conscientiousness remained significant. Our prospective data corroborate evidence from previous cross-sectional studies that patients with ABI experience larger declines in Extraversion and Conscientiousness than the general population. Whereas the effect on Conscientiousness was unique to patients with ABI, the decline in Extraversion was also observed in participants with other impairments. Copyright © 2016 Elsevier Inc. All rights reserved.

Solar-Panel Dust Accumulation and Cleanings

Science.gov (United States)

2005-01-01

Air-fall dust accumulates on the solar panels of NASA's Mars Exploration Rovers, reducing the amount of sunlight reaching the solar arrays. Pre-launch models predicted steady dust accumulation. However, the rovers have been blessed with occasional wind events that clear significant amounts of dust from the solar panels. This graph shows the effects of those panel-cleaning events on the amount of electricity generated by Spirit's solar panels. The horizontal scale is the number of Martian days (sols) after Spirit's Jan. 4, 2005, (Universal Time) landing on Mars. The vertical scale indicates output from the rover's solar panels as a fraction of the amount produced when the clean panels first opened. Note that the gradual declines are interrupted by occasional sharp increases, such as a dust-cleaning event on sol 420.

Panel fabrication utilizing GaAs solar cells

Science.gov (United States)

Mardesich, N.

1984-01-01

The development of the GaAs solar cells for space applications is described. The activities in the fabrication of GaAs solar panels are outlined. Panels were fabricated while introducing improved quality control, soldering laydown and testing procedures. These panels include LIPS II, San Marco Satellite, and a low concentration panel for Rockwells' evaluation. The panels and their present status are discussed.

Attic Retrofits Using Nail-Base Insulated Panels

Energy Technology Data Exchange (ETDEWEB)

Mallay, David [Home Innovation Research Labs; Kochkin, Vladimir [Home Innovation Research Labs

2018-03-26

This project developed and demonstrated a roof/attic energy retrofit solution using nail-base insulated panels for existing homes where traditional attic insulation approaches are not effective or feasible. Nail-base insulated panels (retrofit panels) consist of rigid foam insulation laminated to one face of a wood structural panel. The prefabricated panels are installed above the existing roof deck during a reroofing effort.

Analysing sensory panel performance in a proficiency test using the PanelCheck software

DEFF Research Database (Denmark)

Tomic, O.; Luciano, G.; Nilsen, A.

2010-01-01

Check software, a workflow is proposed that guides the user through the data analysis process. This allows practitioners and non-statisticians to get an overview over panel performances in a rapid manner without the need to be familiar with details on the statistical methods. Visualisation of data analysis...... results plays an important role as this provides a time saving and efficient way of screening and investigating sensory panel performances. Most of the statistical methods used in this paper are available in the open source software PanelCheck, which may be downloaded and used for free....

Investigation on Wall Panel Sandwiched With Lightweight Concrete

Science.gov (United States)

Lakshmikandhan, K. N.; Harshavardhan, B. S.; Prabakar, J.; Saibabu, S.

2017-08-01

The rapid population growth and urbanization have made a massive demand for the shelter and construction materials. Masonry walls are the major component in the housing sector and it has brittle characteristics and exhibit poor performance against the uncertain loads. Further, the structure requires heavier sections for carrying the dead weight of masonry walls. The present investigations are carried out to develop a simple, lightweight and cost effective technology for replacing the existing wall systems. The lightweight concrete is developed for the construction of sandwich wall panel. The EPS (Expanded Polystyrene) beads of 3 mm diameter size are mixed with concrete and developed a lightweight concrete with a density 9 kN/m3. The lightweight sandwich panel is cast with a lightweight concrete inner core and ferrocement outer skins. This lightweight wall panel is tested for in-plane compression loading. A nonlinear finite element analysis with damaged plasticity model is carried out with both material and geometrical nonlinearities. The experimental and analytical results were compared. The finite element study predicted the ultimate load carrying capacity of the sandwich panel with reasonable accuracy. The present study showed that the lightweight concrete is well suitable for the lightweight sandwich wall panels.

Mounting clips for panel installation

Science.gov (United States)

Cavieres, Andres; Al-Haddad, Tristan; Goodman, Joseph; Valdes, Francisco

2017-02-14

An exemplary mounting clip for removably attaching panels to a supporting structure comprises a base, spring locking clips, a lateral flange, a lever flange, and a spring bonding pad. The spring locking clips extend upwardly from the base. The lateral flange extends upwardly from a first side of the base. The lateral flange comprises a slot having an opening configured to receive at least a portion of one of the one or more panels. The lever flange extends outwardly from the lateral flange. The spring bonding flange extends downwardly from the lever flange. At least a portion of the first spring bonding flange comprises a serrated edge for gouging at least a portion of the one or more panels when the one or more panels are attached to the mounting clip to electrically and mechanically couple the one or more panels to the mounting clip.

A Longitudinal Study of the Impact of an Environmental Action

Science.gov (United States)

Rioux, Liliane; Pasquier, Daniel

2013-01-01

In a previous study, we investigated the impact of an awareness-raising campaign on the behaviour of secondary school children in the Centre Region of France, regarding the recycling of used batteries. But, was it a question of pro-environmental behaviour or simply an environmental action? To answer this question, a three-year longitudinal study…

Panel data analysis of cardiotocograph (CTG) data.

Science.gov (United States)

Horio, Hiroyuki; Kikuchi, Hitomi; Ikeda, Tomoaki

2013-01-01

Panel data analysis is a statistical method, widely used in econometrics, which deals with two-dimensional panel data collected over time and over individuals. Cardiotocograph (CTG) which monitors fetal heart rate (FHR) using Doppler ultrasound and uterine contraction by strain gage is commonly used in intrapartum treatment of pregnant women. Although the relationship between FHR waveform pattern and the outcome such as umbilical blood gas data at delivery has long been analyzed, there exists no accumulated FHR patterns from large number of cases. As time-series economic fluctuations in econometrics such as consumption trend has been studied using panel data which consists of time-series and cross-sectional data, we tried to apply this method to CTG data. The panel data composed of a symbolized segment of FHR pattern can be easily handled, and a perinatologist can get the whole FHR pattern view from the microscopic level of time-series FHR data.

ALDS 1978 panel review. [PNL

Energy Technology Data Exchange (ETDEWEB)

Hall, D.L. (ed.)

1979-08-01

Pacific Northwest Laboratory (PNL) is examining the analysis of large data sets (ALDS). After one year's work, a panel was convened to evaluate the project. This document is the permanent record of that panel review. It consists of edited transcripts of presentations made to the panel by the PNL staff, a summary of the responses of the panel to these presentations, and PNL's plans for the development of the ALDS project. The representations of the PNL staff described various aspects of the project and/or the philosophy surrounding the project. Supporting materials appear in appendixes. 20 figures, 4 tables. (RWR)

LONGITUDINAL STUDY OF SEMEN QUALITY AFTER INTERMITTENT EXPOSURE TO AIR POLLUTION

Science.gov (United States)

LONGITUDINAL STUDY OF SEMEN QUALITY AFTER INTERMITTENT EXPOSURE TO AIR POLLUTION. J. Rubes*, D. Zudova*, Veterinary Research Institute, Brno, CR, S.G. Selevan*, US EPA/ORD/NCEA, Washington, DC, D.P. Evenson, South Dakota State University, Brookings, SD, and S.D. Perreault, US ...

Analytical and Numerical Study of Foam-Filled Corrugated Core Sandwich Panels under Low Velocity Impact

Directory of Open Access Journals (Sweden)

Mohammad Nouri Damghani

2016-05-01

Full Text Available Analytical and finite element simulations are used to predict the effect of core density on the energy absorption of composite sandwich panels under low-velocity impact. The composite sandwich panel contains two facesheets and a foam-filled corrugated core. Analytical model is defined as a two degree-of-freedom system based on equivalent mass, spring, and dashpot to predict the local and global deformation response of a simply supported panel. The results signify a good agreement between analytical and numerical predictions.

Effects of poison panel shrinkage and gaps on fuel storage rack reactivity

International Nuclear Information System (INIS)

Boyd, W.A.; Mueller, D.E.

1988-01-01

Fixed poison panels are used in spent fuel rack designs to increase enrichment limits and reduce cell spacing; therefore, assurances that the maximum rack reactivity will meet the design limit (0.95) throughout the lifetime of the racks depend on the continued effectiveness of the poison with time. Industry data have shown that poison panels will shrink under irradiated conditions. From recent data, however, poison panels have been found to have gaps spanning their width after relatively short operating periods. This paper presents results of studies showing the fuel rack reactivity changes associated with poison panel shrinkage and formation of gaps. The discovery of gaps in the fuel rack poison panels at an operating plant raises concerns regarding the effectiveness of the poison over the lifetime of the fuel racks. Studies performed to evaluate the effect of the poison panel shrinkage on reactivity show that reactivity changes from zero to several percent are possible depending on the initial panel size. Results of recent studies show that some gaps can be accommodated in the fuel rack poison panels at the fuel midplane without causing the fuel rack K eff limit to be exceeded. With worst-case assumptions concerning gap size and the number of panels affected, other actions will likely be required to show that the rack K eff design limit will not be exceeded

Analytical Modelling and Simulation of Photovoltaic Panels and Arrays

Directory of Open Access Journals (Sweden)

H. Bourdoucen

2007-12-01

Full Text Available In this paper, an analytical model for PV panels and arrays based on extracted physical parameters of solar cells is developed. The proposed model has the advantage of simplifying mathematical modelling for different configurations of cells and panels without losing efficiency of PV system operation. The effects of external parameters, mainly temperature and solar irradiance have been considered in the modelling. Due to their critical effects on the operation of the panel, effects of series and shunt resistances were also studied. The developed analytical model has been easily implemented, simulated and validated using both Spice and Matlab packages for different series and parallel configurations of cells and panels. The results obtained with these two programs are in total agreement, which make the proposed model very useful for researchers and designers for quick and accurate sizing of PV panels and arrays.

Evaluation of brain ageing: a quantitative longitudinal MRI study over 7 years

Energy Technology Data Exchange (ETDEWEB)

Gracien, Rene-Maxime; Nuernberger, Lucas; Hof, Stephanie-Michelle; Reitz, Sarah C.; Hilker-Roggendorf, Ruediger; Baudrexel, Simon [Goethe University, Department of Neurology, Frankfurt/Main (Germany); Goethe University, Brain Imaging Center, Frankfurt/Main (Germany); Hok, Pavel [Goethe University, Department of Neurology, Frankfurt/Main (Germany); Goethe University, Brain Imaging Center, Frankfurt/Main (Germany); Palacky University, Department of Neurology, Olomouc (Czech Republic); Rueb, Udo [Goethe University, Dr. Senckenberg Chronomedical Institute, Frankfurt/Main (Germany); Steinmetz, Helmuth [Goethe University, Department of Neurology, Frankfurt/Main (Germany); Klein, Johannes C. [Goethe University, Department of Neurology, Frankfurt/Main (Germany); Goethe University, Brain Imaging Center, Frankfurt/Main (Germany); University of Oxford, Nuffield Department of Clinical Neurosciences, Oxford (United Kingdom); Deichmann, Ralf [Goethe University, Brain Imaging Center, Frankfurt/Main (Germany)

2017-04-15

T1 relaxometry is a promising tool for the assessment of microstructural changes during brain ageing. Previous cross-sectional studies demonstrated increasing T1 values in white and decreasing T1 values in grey matter over the lifetime. However, these findings have not yet been confirmed on the basis of a longitudinal study. In this longitudinal study over 7 years, T1 relaxometry was used to investigate the dynamics of age-related microstructural changes in older healthy subjects. T1 mapping was performed in 17 healthy subjects (range 51-77 years) at baseline and after 7 years. Advanced cortical and white matter segmentation was used to determine mean T1 values in the cortex and white matter. The analysis revealed a decrease of mean cortical T1 values over 7 years, the rate of T1 reduction being more prominent in subjects with higher age. T1 decreases were predominantly localized in the lateral frontal, parietal and temporal cortex. In contrast, mean white matter T1 values remained stable. T1 mapping is shown to be sensitive to age-related microstructural changes in healthy ageing subjects in a longitudinal setting. Data of a cohort in late adulthood and the senescence period demonstrate a decrease of cortical T1 values over 7 years, most likely reflecting decreasing water content and increased iron concentrations. (orig.)

Evaluation of brain ageing: a quantitative longitudinal MRI study over 7 years

International Nuclear Information System (INIS)

Gracien, Rene-Maxime; Nuernberger, Lucas; Hof, Stephanie-Michelle; Reitz, Sarah C.; Hilker-Roggendorf, Ruediger; Baudrexel, Simon; Hok, Pavel; Rueb, Udo; Steinmetz, Helmuth; Klein, Johannes C.; Deichmann, Ralf

2017-01-01

T1 relaxometry is a promising tool for the assessment of microstructural changes during brain ageing. Previous cross-sectional studies demonstrated increasing T1 values in white and decreasing T1 values in grey matter over the lifetime. However, these findings have not yet been confirmed on the basis of a longitudinal study. In this longitudinal study over 7 years, T1 relaxometry was used to investigate the dynamics of age-related microstructural changes in older healthy subjects. T1 mapping was performed in 17 healthy subjects (range 51-77 years) at baseline and after 7 years. Advanced cortical and white matter segmentation was used to determine mean T1 values in the cortex and white matter. The analysis revealed a decrease of mean cortical T1 values over 7 years, the rate of T1 reduction being more prominent in subjects with higher age. T1 decreases were predominantly localized in the lateral frontal, parietal and temporal cortex. In contrast, mean white matter T1 values remained stable. T1 mapping is shown to be sensitive to age-related microstructural changes in healthy ageing subjects in a longitudinal setting. Data of a cohort in late adulthood and the senescence period demonstrate a decrease of cortical T1 values over 7 years, most likely reflecting decreasing water content and increased iron concentrations. (orig.)

A micromechanical study of porous composites under longitudinal shear and transverse normal loading

DEFF Research Database (Denmark)

Ashouri Vajari, Danial

2015-01-01

The mechanical response of porous unidirectional composites under transverse normal and longitudinal shear loading is studied using the finite element analysis. The 3D model includes discrete and random distribution of fibers and voids. The micromechanical failure mechanisms are taken into account....... Finally, the computational prediction of the porous composite in the transverse normal-longitudinal shear stress space is obtained and compared with Puck's model. The results show that both interfaces with low fracture toughness and microvoids with even small void volume fraction can significantly reduce...

Language Learning at Key Stage 2: Findings from a Longitudinal Study

Science.gov (United States)

Cable, Carrie; Driscoll, Patricia; Mitchell, Rosamond; Sing, Sue; Cremin, Teresa; Earl, Justine; Eyres, Ian; Holmes, Bernardette; Martin, Cynthia; Heins, Barbara

2012-01-01

This paper discusses some of the findings from a 3-year longitudinal study of language learning in the upper stage of English primary schools, i.e. at Key Stage 2. This largely qualitative study (commissioned by the then Department for Children, Schools and Families) was designed to explore and document developing provision and practice in a…

A Longitudinal Study of Environmental and Outdoor Education: A Cultural Change

Science.gov (United States)

Tal, Tali; Morag, Orly

2013-01-01

In this case-study, we present a longitudinal study of one elementary (grades 1-6) school's environmental education (EE) in order to understand the ways in which the school culture supports outdoor EE as a critical component of their science education program. The school, which was known for its school-based EE curriculum that encompasses an…

Modal analysis and acoustic transmission through offset-core honeycomb sandwich panels

Science.gov (United States)

Mathias, Adam Dustin

The work presented in this thesis is motivated by an earlier research that showed that double, offset-core honeycomb sandwich panels increased thermal resistance and, hence, decreased heat transfer through the panels. This result lead to the hypothesis that these panels could be used for acoustic insulation. Using commercial finite element modeling software, COMSOL Multiphysics, the acoustical properties, specifically the transmission loss across a variety of offset-core honeycomb sandwich panels, is studied for the case of a plane acoustic wave impacting the panel at normal incidence. The transmission loss results are compared with those of single-core honeycomb panels with the same cell sizes. The fundamental frequencies of the panels are also computed in an attempt to better understand the vibrational modes of these particular sandwich-structured panels. To ensure that the finite element analysis software is adequate for the task at hand, two relevant benchmark problems are solved and compared with theory. Results from these benchmark results compared well to those obtained from theory. Transmission loss results from the offset-core honeycomb sandwich panels show increased transmission loss, especially for large cell honeycombs when compared to single-core honeycomb panels.

EFFECT OF REFLECTOR APPLICATION ON PV PANEL PERFORMANCE UNDER EGYPTIAN CONDITIONS

Directory of Open Access Journals (Sweden)

Mamdouh Abbas HELMY

2014-10-01

Full Text Available The proposed approach in the present study is to employ a mirror augmented PV solar panel to track the sun and reflect rays on to the PV panel. Its performance was compared with same PV module without reflector under the same environmental conditions. The mirror augmented solar PV panel tracked sun from East to West along the daytime in Winter 2011 with tilt angle0.523 rad (30 deg for panel and 0.122 rad (7deg for mirror which are estimated by experiment. The average energy output values of 1.11 and 0.95 kWh/day were recorded for panel with and without mirror, respectively. The average daily .panel values of 12.6 and 11.02 % were recorded for panel with and without mirror, respectively. The increase percentages in the output of panel and discharge differs with the solar radiation along daytime. The application of mirror is an efficient and an effective way to enhance the performance of solar photovoltaic pumping system with the same panel area.

The contingency of intermedia agenda setting: a longitudinal study in Belgium

NARCIS (Netherlands)

Vliegenthart, R.; Walgrave, S.

2008-01-01

This large-scale study investigates how intermedia agenda-setting effects are moderated by five factors: (1) lag length; (2) medium type; (3) language/institutional barriers; (4) issue type; and (5) election or non-election context. Longitudinal analyses of daily attention to twenty-five issues in

Panel acoustic contribution analysis.

Science.gov (United States)

Wu, Sean F; Natarajan, Logesh Kumar

2013-02-01

Formulations are derived to analyze the relative panel acoustic contributions of a vibrating structure. The essence of this analysis is to correlate the acoustic power flow from each panel to the radiated acoustic pressure at any field point. The acoustic power is obtained by integrating the normal component of the surface acoustic intensity, which is the product of the surface acoustic pressure and normal surface velocity reconstructed by using the Helmholtz equation least squares based nearfield acoustical holography, over each panel. The significance of this methodology is that it enables one to analyze and rank relative acoustic contributions of individual panels of a complex vibrating structure to acoustic radiation anywhere in the field based on a single set of the acoustic pressures measured in the near field. Moreover, this approach is valid for both interior and exterior regions. Examples of using this method to analyze and rank the relative acoustic contributions of a scaled vehicle cabin are demonstrated.

Advanced Solar Panel Designs

Science.gov (United States)

Ralph, E. L.; Linder, E. B.

1995-01-01

Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 sq cm coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual-junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 sq cm coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg.

Evaluation of photovoltaic panel temperature in realistic scenarios

International Nuclear Information System (INIS)

Du, Yanping; Fell, Christopher J.; Duck, Benjamin; Chen, Dong; Liffman, Kurt; Zhang, Yinan; Gu, Min; Zhu, Yonggang

2016-01-01

Highlights: • The developed realistic model captures more reasonably the thermal response and hysteresis effects. • The predicted panel temperature is as high as 60 °C under a solar irradiance of 1000 W/m"2 in no-wind weather. • In realistic scenarios, the thermal response normally takes 50–250 s. • The actual heating effect may cause a photoelectric efficiency drop of 2.9–9.0%. - Abstract: Photovoltaic (PV) panel temperature was evaluated by developing theoretical models that are feasible to be used in realistic scenarios. Effects of solar irradiance, wind speed and ambient temperature on the PV panel temperature were studied. The parametric study shows significant influence of solar irradiance and wind speed on the PV panel temperature. With an increase of ambient temperature, the temperature rise of solar cells is reduced. The characteristics of panel temperature in realistic scenarios were analyzed. In steady weather conditions, the thermal response time of a solar cell with a Si thickness of 100–500 μm is around 50–250 s. While in realistic scenarios, the panel temperature variation in a day is different from that in steady weather conditions due to the effect of thermal hysteresis. The heating effect on the photovoltaic efficiency was assessed based on real-time temperature measurement of solar cells in realistic weather conditions. For solar cells with a temperature coefficient in the range of −0.21%∼−0.50%, the current field tests indicated an approximate efficiency loss between 2.9% and 9.0%.

Children in care (CIC): A Danish longitudinal study

DEFF Research Database (Denmark)

Egelund, Tine; Hestbæk, Anne-Dorthe

This paper presents results describing what characterizes young, Danish children in care and their parents, and, furthermore, discusses social policy implications of the complex psychosocial disadvantages influencing the families. The paper is based on a longitudinal study of all Danish children......, born in 1995, who currently are or formerly have been placed in care. The first data collection was conducted in the spring 2003, where the children were 7-8 years of age. It is the intention to follow up the children every third year during childhood, adolescence, and adult life. At each new data...

Durability study on material of wooden panel elements used for the old living hut built in 1969 at Syowa Station, Antarctica

Directory of Open Access Journals (Sweden)

Toshimasa Konishi

2002-09-01

Full Text Available The purpose of this study is to determine the durability of the old living hut built in 1969 at Syowa Station, Japan's permanent Antarctic observation facility, especially of its wooden panels. The hut, of high floor type wooden panel construction, was built in January 1969. To determine the durability, part of the hut, which was brought back to Japan after 30 years, was rebuilt, then taken apart again under controlled test conditions. Tests included visual observation, testing of the wooden material, and testing of the performance of the thermal insulation material. The results showed that the material in the roof panels deteriorated considerably more than that in the walls and floors. In the severe polar conditions, the strength of the overall structure depends heavily on the joints between panels. It is clear that material on the indoor sides, and in the interiors of the panels, hardly deteriorated at all after 30 years.

Honeycomb metal panel

International Nuclear Information System (INIS)

1979-01-01

Product constituted by a honeycomb metal panel that can be employed to advantage for manufacturing lagging by sandwiching it between two plane sheets, utilized in particular in the nuclear industry where lagging has to have a very long life strength. The honeycomb metal panel is made of an expanded metal extrusion previously cut so as to form, after additional drawing, a honeycomb structure with square or rectangular cells with a plane surface [fr

Exascale Workshop Panel Report Meeting

Energy Technology Data Exchange (ETDEWEB)

Khaleel, Mohammad A.

2010-07-01

The Exascale Review Panel consists of 12 scientists and engineers with experience in various aspects of high-performance computing and its application, development, and management. The Panel hear presentations by several representatives of the workshops and town meetings convened over the past few years to examine the need for exascale computation capability and the justification for a U.S. Department of Energy (DOE) program to develop such capability. This report summarizes information provided by the presenters and substantial written reports to the Panel in advance of the meeting in Washington D.C. on January 19-20, 2010. The report also summarizes the Panel's conclusions with regard to the justification of a DOE-led exascale initiative.

Environmental Performance of North American Wood Panel Manufacturing

Science.gov (United States)

R. Bergman; D. Kaestner; A. Taylor

2015-01-01

Manufacturing building products such as wood panels has environmental impacts, including contributions to climate change. This paper is a compilation of four studies quantifying these impacts using the life-cycle assessment (LCA) method on five wood-based panel products made in North America during 2012. LCA is an internationally accepted and standardized method for...

Environmental monitoring through the use of exposure panels

International Nuclear Information System (INIS)

Hillman, R.E.

1975-01-01

Exposure panels made of white pine with a transite facing are useful for assessing population and community changes in both polluted and unpolluted waters. Their uniform size and shape and the ease with which they can be handled makes them ideal for sampling a wide variety of sessile plants and animals, and those motile forms usually associated with sessile communities. Data from an ecological study at Millstone Point are used as examples of the kinds of information provided through the use of exposure panels as environmental monitors. Species diversity indexes for both algal and annelid populations as they occurred on panels from 1968 through 1973 were calculated. Regression analyses over time showed increases in diversity indexes since the program began, indicating possible changes in water quality. For the period of October 1971 through September 1972, the number of phyla found on panels exposed at Millstone Point, New Haven Harbor, and Stamford Harbor were not significantly different, but far more species were found on the Millstone Point panels. (U.S.)

X-Ray Radiographic Study of some Panel Painting Icons from the Beginning of the XX Century

Directory of Open Access Journals (Sweden)

Ioan EMANDI

2011-09-01

Full Text Available Nondestructive investigation methods with penetrating radiations, such as digital radiography and computed tomography proved to be very useful not only in assessing the cultural heritage, but also but also in any restoration and conservation activity by supplying a multitude of micro-structural details regarding a great diversity of works of art. Consequently, present paper presents two case studies regarding the use of digital radiography in investigating panel icons from the Popa Tatu Church, Bucharest. In both cases it was possible to evidence not only the actual state of conservation of wooden panels but also fragments of the oil picture, allowing a better planning of the future conservation work.

Self-transcendence and depression among AIDS Memorial Quilt panel makers.

Science.gov (United States)

Kausch, Kurt D; Amer, Kim

2007-06-01

Self-transcendence is a process that can help individuals reestablish well-being after experiencing a significant, life-altering event. In this study, we sought to identify the relationship between self-transcendence and depression in individuals who lost loved ones to HIV/AIDS and to describe and compare self-transcendence, self-transcendence variables of acceptance and spirituality, and depression among bereaved individuals who created AIDS Memorial Quilt panels with those who did not. The findings support Reed's self-transcendence theory, with inverse correlations between self-transcendence and depression obtained from both the total group and the panel makers. Significant differences were also found between certain self-transcendence variables and depression among the study participants related to gender and ethnicity. In addition, thematic analysis of panel maker interviews revealed five themes: Quilt panel making provides validation, Quilt panel making creates a living memory, liberating acceptance of loss, community of survivors, and connection to a higher power. These findings assist in understanding the complexities of the grief process and support the usefulness of Quilt panel making as an intervention for coping with grief related to HIV/AIDS.

The gain of single-axis tracked panel according to extraterrestrial radiation

International Nuclear Information System (INIS)

Chang, T.P.

2009-01-01

In the present study, the gain in extraterrestrial radiation received by a single-axis tracked panel relative to a fixed panel was systematically analyzed over a specific period of time. The dynamic angle that the tracked panel should rotate by in order to follow the sun was derived through a series of spherical trigonometric procedures. The instantaneous incident angle of sunlight upon the panel was then calculated, assuming that the panel would simultaneously follow the sun's position. Thus, instantaneous increments of solar energy received by the tracked panel relative to the fixed panel are originally presented. The results show that the angle the tracked panel has to rotate by is 0 deg. at solar noon, and increases towards dawn or dusk. The incident angle of sunlight upon the tracked panel is always smaller than that upon the fixed panel, except at solar noon. As for panels installed with a yearly optimal tilt angle in Taipei, the gains are between 36.3% and 62.1% for four particular days of year, between 37.8% and 60.8% for the four seasons and 49.3% over the entire year. The amount of radiation collected by the tracked panel is enhanced as the maximum rotation angle is increased. The irradiation ratio of the tracked panel to the fixed panel is close to 1.5 for latitudes below 65 deg. and gradually increases for latitudes above this. The yearly optimal tilt angle of a south-facing fixed panel is approximately equal to 0.9 multiplied by the latitude (i.e. 0.9 x φ) for latitudes below 65 deg. and is about 56 + 0.4 x (φ - 65) otherwise

How do Rumination and Social Problem Solving Intensify Depression? A Longitudinal Study.

Science.gov (United States)

Hasegawa, Akira; Kunisato, Yoshihiko; Morimoto, Hiroshi; Nishimura, Haruki; Matsuda, Yuko

2018-01-01

In order to examine how rumination and social problem solving intensify depression, the present study investigated longitudinal associations among each dimension of rumination and social problem solving and evaluated aspects of these constructs that predicted subsequent depression. A three-wave longitudinal study, with an interval of 4 weeks between waves, was conducted. Japanese university students completed the Beck Depression Inventory-Second Edition, Ruminative Responses Scale, Social Problem-Solving Inventory-Revised Short Version, and Interpersonal Stress Event Scale on three occasions 4 weeks apart ( n  = 284 at Time 1, 198 at Time 2, 165 at Time 3). Linear mixed models were analyzed to test whether each variable predicted subsequent depression, rumination, and each dimension of social problem solving. Rumination and negative problem orientation demonstrated a mutually enhancing relationship. Because these two variables were not associated with interpersonal conflict during the subsequent 4 weeks, rumination and negative problem orientation appear to strengthen each other without environmental change. Rumination and impulsivity/carelessness style were associated with subsequent depressive symptoms, after controlling for the effect of initial depression. Because rumination and impulsivity/carelessness style were not concurrently and longitudinally associated with each other, rumination and impulsive/careless problem solving style appear to be independent processes that serve to intensify depression.

On the Use of Diversity Measures in Longitudinal Sequencing Studies of Microbial Communities.

Science.gov (United States)

Wagner, Brandie D; Grunwald, Gary K; Zerbe, Gary O; Mikulich-Gilbertson, Susan K; Robertson, Charles E; Zemanick, Edith T; Harris, J Kirk

2018-01-01

Identification of the majority of organisms present in human-associated microbial communities is feasible with the advent of high throughput sequencing technology. As substantial variability in microbiota communities is seen across subjects, the use of longitudinal study designs is important to better understand variation of the microbiome within individual subjects. Complex study designs with longitudinal sample collection require analytic approaches to account for this additional source of variability. A common approach to assessing community changes is to evaluate the change in alpha diversity (the variety and abundance of organisms in a community) over time. However, there are several commonly used alpha diversity measures and the use of different measures can result in different estimates of magnitude of change and different inferences. It has recently been proposed that diversity profile curves are useful for clarifying these differences, and may provide a more complete picture of the community structure. However, it is unclear how to utilize these curves when interest is in evaluating changes in community structure over time. We propose the use of a bi-exponential function in a longitudinal model that accounts for repeated measures on each subject to compare diversity profiles over time. Furthermore, it is possible that no change in alpha diversity (single community/sample) may be observed despite the presence of a highly divergent community composition. Thus, it is also important to use a beta diversity measure (similarity between multiple communities/samples) that captures changes in community composition. Ecological methods developed to evaluate temporal turnover have currently only been applied to investigate changes of a single community over time. We illustrate the extension of this approach to multiple communities of interest (i.e., subjects) by modeling the beta diversity measure over time. With this approach, a rate of change in community

Late urologic morbidity in 177 consecutive patients after radiotherapy for cervical carcinoma: a longitudinal study

International Nuclear Information System (INIS)

Lajer, Henrik; Thranov, Ingrid R.; Skovgaard, Lene T.; Engelholm, Svend Aa

2002-01-01

Purpose: To provide longitudinal data on urologic morbidity after radiotherapy and brachytherapy for cervical carcinoma. Methods and Materials: Five-year longitudinal urologic morbidity data were recorded from 177 consecutive patients of median age 59 years (range: 22-86 years) with cervical carcinoma receiving radiotherapy with curative intent at the Copenhagen University Hospital, Denmark. FIGO stages (%) were as follows: Stage I (15), Stage II (30), Stage III (54), and Stage IV (1). Late morbidity was calculated as cumulative incidence based on actuarial estimates. Results: The 5-year cumulative incidence based on actuarial estimates of urologic morbidity Grades 1 + 2 + 3, Grades 2 + 3, and Grade 3 were 62%, 32%, and 5%, respectively. Frequencies of urologic morbidity in the 54 recurrence-free survivors at the end of follow-up indicated some reversibility in the case of Grades 1 and 2 morbidity. Conclusion: With the longitudinal design used in the present study, a rate of mild and moderate morbidity higher than that found in most of the previously reported literature was observed, giving cause for concern and underlining the importance of further longitudinal studies on this subject, specifically studies that relate to the background urologic morbidity in the female population, as well as to the fact that urologic morbidity might regress

Fracture Analysis of the FAA/NASA Wide Stiffened Panels

Science.gov (United States)

Seshadri, B. R.; Newman, J. C., Jr.; Dawicke, D. S.; Young, R. D.

1999-01-01

This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the "plane-strain" core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions around a crack front, like plane strain, has to be modeled in order for the critical CTOA fracture criterion to predict wide panel failures from small laboratory tests. In the present study, the critical CTOA value was determined from a wide (unstiffened) panel with anti-buckling guides. The plane-strain core size was estimated from previous fracture analyses and was equal to about the sheet thickness. Rivet flexibility and stiffener failure was based on methods and criteria, like that currently used in industry. STAGS and the CTOA criterion were used to predict load-against-crack extension for the wide panels with a single crack and multiple-site damage cracking at many adjacent rivet holes. Analyses were able to predict stable crack growth and residual strength within a few percent (5%) of stiffened panel tests results but over predicted the buckling failure load on an unstiffened panel with a single crack by 10%.

Grounds of two positions photovoltaic panels

OpenAIRE

Castán Fortuño, Fernando

2008-01-01

The objective of this Master Thesis is to find the optimum positioning for a two positions photovoltaic panel. Hence, it will be implemented a model in order to optimize the energy of the sun that the photovoltaic panel is receiving by its positioning. Likewise this project will include the comparison with other photovoltaic panel systems as the single position photovoltaics panels. Ultimately, it is also going to be designed a system array for the optimized model of two positions photovoltai...

Orbiter radiator panel solar focusing test

Science.gov (United States)

Howell, H. R.; Rankin, J. G.

1983-01-01

Test data are presented which define the area around the Orbiter radiator panels for which the solar reflections are concentrated to one-sun or more. The concave shape of the panels and their specular silver/Teflon coating causes focusing of the reflected solar energy which could have adverse heating effects on equipment or astronaut extravehicular activity (EVA) in the vicinity of the radiator panels. A room ambient test method was utilized with a one-tenth scale model of the radiator panels.

Thermal conductivity of newspaper sandwiched aerated lightweight concrete panel

Energy Technology Data Exchange (ETDEWEB)

Ng, Soon-Ching; Low, Kaw-Sai [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Genting Kelang, Setapak, 53300 Kuala Lumpur, Wilayah Persekutuan (Malaysia)

2010-12-15

Investigation on the thermal conductivity of newspaper sandwiched aerated lightweight concrete (ALC) panels is the main purpose of this study. Various densities of ALC panels ranging from 1700, 1400 and 1100 kg/m{sup 3} with three different aerial intensities of newspaper sandwiched were produced. Investigation was limited to the effect of aerial intensity of newspaper sandwiched and the effect of density of ALC on thermal conductivity. It is found that the thermal conductivity of newspaper sandwiched ALC panels reduced remarkably compared to control ALC panels. The reduction was recorded at 18.0%, 21.8% and 20.7% correspond to densities of 1700, 1400 and 1100 kg/m{sup 3} with just a mere 0.05 g/cm{sup 2} aerial intensity of newspaper sandwiched. Newspaper sandwiched has a significant impact on the performance of thermal conductivity of ALC panels based on regression analysis. (author)

Photovoltaic solar panel for a hybrid PV/thermal system

Energy Technology Data Exchange (ETDEWEB)

Zakharchenko, R.; Licea-Jimenez, L.; Perez-Garcia, S.A.; Perez-Robles, J.F.; Gonzalez-Hernandez, J.; Vorobiev, Y. [CINVESTAV-Queretaro, (Mexico); Vorobiev, P. [Universidad Autonoma de Queretaro, (Mexico). Facultad de Ingenieria; Dehesa-Carrasco, U. [Instituto Tec. Del Istmo, Oaxaco (Mexico). Dep. de Ingenieria Electromecanica

2004-05-01

The hybrid PV-thermal system was studied, with the photovoltaic panel (PVP) area much smaller than that of the solar collector. Performance of the different panels in the system was investigated, in particular, those made of crystalline (c-) Si, {alpha}-Si and CuInSe{sub 2} as well as different materials and constructions for the thermal contact between the panel and the collector. Our conclusion is that the PVP for application in a hybrid system needs a special design providing efficient heat extraction from it. PVP was designed and made. Its study has shown that this design provides the high electrical and thermal efficiency of the hybrid system. (author)

Seismic Evaluation of Structural Insulated Panels in Comparison with Wood-Frame Panels

Directory of Open Access Journals (Sweden)

Stefanie Terentiuk

2014-07-01

Full Text Available Structural Insulated Panel (SIP wall systems have been used in residential and light commercial buildings for the past sixty years. Lack of sufficient published research on racking load performance and limited understanding of the influence of fastener types on seismic response has been a deterrent in widespread use of the wall system in seismically active areas. This paper presents the results of a study involving a total of twenty one 2.4 m × 2.4 m shear walls tested under monotonic and cyclic loading. Four different 114 mm thick SIP panel configurations and one traditional wood frame wall were tested under monotonic loading according to ASTM E 564-06; and thirteen 114 mm thick SIP panels and three wood frame walls were tested under the CUREE loading protocol according to ASTM E 2126-11. Parameters such as fastener type; spline design; hold-down anchor location; and sheathing bearing were adjusted throughout the testing in order to determine their effects on the SIP’s performance. Performance parameters such as peak load and displacement; energy dissipation; allowable drift load capacity and seismic compatibility were determined for all of the specimens. Such parameters were then used to demonstrate the SIP walls’ compatibility with the wood frame walls and to determine the efficiency of the different SIP wall configuration and spline systems employed.

Perceived marginalization and aggression: a longitudinal study with low-educated adolescents.

Science.gov (United States)

Issmer, Christian; Wagner, Ulrich

2015-03-01

Social exclusion can evoke aggression. In the past two decades research has demonstrated this effect both for interpersonal and societal forms of exclusion. In addition, recent violent uprisings, like the London riots in August 2011, have been linked to social exclusion in the media. However, so far there is a lack of longitudinal studies which examine the aggression-enhancing effect of societal-level exclusion (i.e., marginalization) in disadvantaged groups. This research investigates the impact of perceived marginalization on aggression in a sample of N = 181 adolescents with a low educational background by means of a two-wave longitudinal study. The results of structural equation analyses are consistent with the hypothesis that perceived marginalization enhances aggression, and that this effect is mediated by the extent of negative societal meta-stereotypes. Furthermore, the reverse path from aggression to perceptions of marginalization is also significant. We discuss the implications of these findings and highlight practical consequences. © 2014 The British Psychological Society.

A Longitudinal Study of Motivation in Foreign and Second Language Learning Context

Science.gov (United States)

Ordem, Eser

2017-01-01

Although motivation has been one of the most commonly studied subjects in second and foreign language learning in recent decades, it still remains an enigma for learners and teachers. This longitudinal study aimed to follow a student (N = 1) studying German in both second and foreign language environment for three years. The study was descriptive,…

Novel Longitudinal and Propensity Score Matched Analysis of Hands-On Cooking and Nutrition Education versus Traditional Clinical Education among 627 Medical Students

Directory of Open Access Journals (Sweden)

Dominique J. Monlezun

2015-01-01

Full Text Available Background. Physicians are inadequately equipped to respond to the global obesity and nutrition-associated chronic disease epidemics. We investigated superiority of simulation-based medical education with deliberate practice (SBME-DP hands-on cooking and nutrition elective in a medical school-based teaching kitchen versus traditional clinical education for medical students. Materials and Methods. A 59-question panel survey was distributed to an entire medical school twice annually from September 2012 to May 2014. Student diet and attitudes and competencies (DACs counseling patients on nutrition were compared using conditional multivariate logistic regression, propensity score-weighted, and longitudinal panel analyses. Inverse-variance weighted meta-analysis (IVWM was used for planned subgroup analysis by year and treatment estimates across the three methods. Results. Of the available 954 students, 65.72% (n=627 unique students were followed to produce 963 responses. 11.32% (n=109 of responses were from 84 subjects who participated in the elective. SBME-DP versus traditional education significantly improved fruit and vegetable diet (OR = 1.38, 95% CI: 1.07–1.79, p=0.013 and attitudes (OR = 1.81, 95% CI: 1.40–2.35, p<0.001 and competencies (OR = 1.72, 95% CI: 1.54–1.92, p<0.001. Conclusions. This study reports for the first time superiority longitudinally for SBME-DP style nutrition education for medical students which has since expanded to 13 schools.

Physical activity, self-efficacy, and self-esteem: longitudinal relationships in older adults.

Science.gov (United States)

McAuley, Edward; Elavsky, Steriani; Motl, Robert W; Konopack, James F; Hu, Liang; Marquez, David X

2005-09-01

We examined the structure of the expanded version of the Exercise and Self-Esteem Model in a sample of older adults (N = 174; age, M = 66.7 years) across a 4-year period. A panel analysis revealed support for the indirect effects of physical activity (PA) and self-efficacy (SE) on physical self-worth and global esteem through subdomain levels of esteem. These relationships were consistent across the 4-year period. Over time, older adults reporting greater reductions in SE and PA also reported greater reductions in subdomain esteem. This is one of the first studies to examine these relationships longitudinally in the PA domain and offers further support for the hierarchical and multidimensional nature of self-esteem at the physical level. We recommend further testing of the Exercise and Self-Esteem Model, with special attention being paid to assessing multiple aspects of PA and SE.

FEMA DFIRM Panel Scheme Polygons

Data.gov (United States)

Minnesota Department of Natural Resources — This layer contains information about the Flood Insurance Rate Map (FIRM) panel areas. The spatial entities representing FIRM panels are polygons. The polygon for...

21 CFR 516.141 - Qualified expert panels.

Science.gov (United States)

2010-04-01

... choose members for the qualified expert panel in accordance with selection criteria listed in paragraph... whether the proposed qualified expert panel meets the selection criteria prior to the panel beginning its... Committee Act, as amended, 5 U.S.C. App. (b) Criteria for the selection of a qualified expert panel. (1) A...

Six-month longitudinal associations between cognitive functioning and distress among the community-based elderly in Hong Kong: A cross-lagged panel analysis.

Science.gov (United States)

Leung, Chantel Joanne; Cheng, Lewis; Yu, Junhong; Yiend, Jenny; Lee, Tatia M C

2018-07-01

Although previous studies have extensively documented the cross-sectional relationship between cognitive impairment and psychological distress, findings relating to their longitudinal associations remains mixed. The present study examines the longitudinal associations and mutual influence between cognitive functioning and psychological distress across six months among community-dwelling elderly in Hong Kong. A total of 162 older adults (40 males; M age  = 69.8 years, SD = 6.4) were administered objective and subjective measures of cognitive functioning, as well as self-reported ratings of distress, at two time points six months apart. Using structural equation modeling, we tested the cross-lagged relationships between cognitive functioning and distress. Our cross-lagged model indicated that cognitive functioning at baseline significantly predicted subsequent psychological distress. However, distress was not significantly associated with subsequent cognitive functioning. Additionally, the objective and subjective measures of cognitive functioning were not significantly correlated. These findings suggested that distress may occur as a consequence of poorer cognitive functioning in elderly, but not vice versa. The lack of correlation between objective and subjective cognitive measures suggested that the participants may not have adequate insight into their cognitive abilities. The implications of these findings are discussed. Copyright © 2018. Published by Elsevier B.V.

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

Evaluating the longitudinal risk of social vigilance on atherosclerosis: study protocol for the North Texas Heart Study.

Science.gov (United States)

Ruiz, John M; Taylor, Daniel J; Uchino, Bert N; Smith, Timothy W; Allison, Matthew; Ahn, Chul; Johnson, Jillian J; Smyth, Joshua M

2017-08-14

Psychosocial factors are increasingly recognised as important determinants of cardiovascular disease risk. The North Texas Heart Study aims to understand the mechanisms responsible for this association with a focus on social vigilance (ie, scanning the environment for social threats). There is also growing interest in supplementing traditional methods (eg, survey assessment of psychosocial risk paired with cross-sectional and longitudinal health outcomes) with daily or repeated momentary assessment of psychosocial factors. However, there are relatively few longitudinal studies directly comparing these approaches with hard endpoints. The North Texas Heart Study proposes a longitudinal measurement burst design to examine psychosocial determinants of subclinical atherosclerosis. A sample of 300 healthy community participants, stratified by age and gender, will complete survey measures, as well as 2 days of ecological momentary assessment at baseline and at a 2-year follow-up. A range of psychosocial and behavioural factors, objective biomarkers, as well as carotid intima-media thickness (cIMT) will be assessed at both time points. Unadjusted and adjusted models will evaluate cross-sectional associations and determinants of change in the cIMT. The Institutional Review Board at the study coordinating institute (University of North Texas) has approved this study. Positive, negative or inconclusive primary and ancillary findings will be disseminated in scientific journals and conferences. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Impaired Perception of Syllable Stress in Children with Dyslexia: A Longitudinal Study

Science.gov (United States)

Goswami, Usha; Mead, Natasha; Fosker, Tim; Huss, Martina; Barnes, Lisa; Leong, Victoria

2013-01-01

Prosodic patterning is a key structural element of spoken language. However, the potential role of prosodic awareness in the phonological difficulties that characterise children with developmental dyslexia has been little studied. Here we report the first longitudinal study of sensitivity to syllable stress in children with dyslexia, enabling the…

Latino Parental Involvement in Kindergarten: Findings from the Early Childhood Longitudinal Study

Science.gov (United States)

Durand, Tina M.

2011-01-01

Parental involvement in children's schooling is an important component of children's early school success. Few studies have examined this construct exclusively among Latino families. Using data from the Early Childhood Longitudinal Study (ECLS-K), the present investigation (N = 2,051) explored relations between Latino parents' home and school…

Conditions for Ubiquitous Computing: What Can Be Learned from a Longitudinal Study

Science.gov (United States)

Lei, Jing

2010-01-01

Based on survey data and interview data collected over four academic years, this longitudinal study examined how a ubiquitous computing project evolved along with the changes in teachers, students, the human infrastructure, and technology infrastructure in the school. This study also investigated what conditions were necessary for successful…

Energy efficiency and indoor thermal perception. A comparative study between radiant panel and portable convective heaters

Energy Technology Data Exchange (ETDEWEB)

Ali, Ahmed Hamza H.; Morsy, Mahmoud Gaber [Department of Mechanical Engineering, Faculty of Engineering, Assiut University, Assiut, 71516 (Egypt)

2010-11-15

This study investigates experimentally the thermal perception of indoor environment for evaluating the ability of radiant panel heaters to produce thermal comfort for space occupants as well as the energy consumption in comparison with conventional portable natural convective heaters. The thermal perception results show that, compared with conventional convection heater, a radiantly heated office room maintains a lower ambient air temperature while providing equal levels of thermal perception on the thermal dummy head as the convective heater and saves up to 39.1% of the energy consumption per day. However, for human subjects' vote experiments, the results show that for an environmentally controlled test room at outdoor environment temperatures of 0C and 5C, using two radiant panel heaters with a total capacity of 580 W leads to a better comfort sensation than the conventional portable natural convective heater with a 670 W capacity, with an energy saving of about 13.4%. In addition, for an outdoor environment temperature of 10C, using one radiant panel heater with a capacity of 290 W leads to a better comfort sensation than the conventional convection heater with a 670 W capacity, with an energy saving of about 56.7%. From the analytical results, it is found that distributing the radiant panel heater inside the office room, one on the wall facing the window and the other on the wall close to the window, provides the best operative temperature distribution within the room.

Classroom Connectivity and Algebra 1 Achievement: A Three-Year Longitudinal Study

Science.gov (United States)

Irving, Karen E.; Pape, Stephen J.; Owens, Douglas T.; Abrahamson, Louis; Silver, David; Sanalan, Vehbi A.

2016-01-01

Findings from three years of a longitudinal randomized control trial involving a national U.S. sample of Algebra 1 teachers and students are reported. The study examines the effects of a connected classroom technology (CCT) professional development and classroom intervention on student achievement when compared to classroom instruction with…

75 FR 82376 - North American Free Trade Agreement, Article 1904 NAFTA Panel Reviews; Request for Panel Review

Science.gov (United States)

2010-12-30

... Mexico and the People's Republic of China. This determination was published in the Federal Register (75... Panel Review. SUMMARY: On December 22, 2010, the Government of Mexico filed a First Request for Panel... Government of Mexico established Rules of Procedure for Article 1904 Binational Panel Reviews (``Rules...

Development and evaluation of aerogel-filled BMI sandwich panels for thermal barrier applications

Directory of Open Access Journals (Sweden)

A. Dineshkumar

2016-07-01

Full Text Available This study details a fabrication methodology envisaged to manufacture Glass/BMI honeycomb core aerogel-filled sandwich panels. Silica aerogel granules are used as core fillers to provide thermal insulation properties with little weight increase. Experimental heat transfer studies are conducted on these panels to study the temperature distribution between their two surfaces. Numerical studies are also carried out to validate the results. Despite exhibiting good thermal shielding capabilities, the Glass/BMI sandwich panels are found to oxidise at 180 ºC if exposed directly to heat. In order to increase the temperature bearing capacity and the operating temperature range for these panels, a way of coating them from outside with high temperature spray paint was tried. With a silicone-based coating, the temperature sustainability of these sandwich panels is found to increase to 350 ºC. This proved the effectiveness of the formed manufacturing process, selected high temperature coating, the coating method as well as the envisaged sandwich panel concept.

Weaving leadership longitudinally: a qualitative study on faculty development

OpenAIRE

Joyce, Pauline

2015-01-01

Purpose The purpose of this study was to explore if faculty who undertake teacher preparation, which has a leadership intervention across each module, are better prepared to take on educational leadership roles. Methods A cross sectional qualitative approach was used as part of a longitudinal evaluation of a program. The aim was to explore the perceptions of a purposive sample across three cohorts of students. Data was collected via semi-structured interviews and were analyzed by thema...

Secondary Education and Health Outcomes in Young People from the Cape Area Panel Study (CAPS)

Science.gov (United States)

2016-01-01

Aim Education is one of the strongest social determinants of health, yet previous literature has focused on primary education. We examined whether there are additional benefits to completing upper secondary compared to lower secondary education in a middle-income country. Methods We performed a longitudinal analysis of the Cape Area Panel Study, a survey of adolescents living in South Africa. We undertook causal modeling using structural marginal models to examine the association between level of education and various health outcomes, using inverse probability weighting to control for sex, age, ethnicity, home language, income, whether employed in past year, region of birth, maternal educational status, marital status, whether currently pregnant and cognitive ability. Educational attainment was defined as primary (grades 1–7), lower secondary (grades 8–9) or upper secondary (grades 10–12). Results Of 3,432 participants, 165 (4.8%) had completed primary education, 646 (18.8%) lower secondary and 2,621 (76.3%) upper secondary. Compared to those completing lower secondary, males completing upper secondary education were less likely to have a health problem (OR 0.49; 95%CI 0.27–0.88; p = 0.02); describe their health as poor (0.52; 0.29–0.95; p = 0.03) or report that health interferes with daily life (0.54; 0.29–0.99; p = 0.047). Females were less likely to have been pregnant (0.45; 0.33–0.61; peducation and alcohol use, psychological distress, obesity, increased waist circumference or hypertension. Conclusion Completing upper secondary education was associated with improved health outcomes compared with lower secondary education. Expanding upper secondary education offers middle-income countries an effective way of improving adolescent health. PMID:27280408

A longitudinal study of structural brain network changes with normal aging

Directory of Open Access Journals (Sweden)

Kai eWu

2013-04-01

Full Text Available The aim of this study was to investigate age-related changes in the topological organization of structural brain networks by applying a longitudinal design over 6 years. Structural brain networks were derived from measurements of regional gray matter volume and were constructed in age-specific groups from baseline and follow-up scans. The structural brain networks showed economical small-world properties, providing high global and local efficiency for parallel information processing at low connection costs. In the analysis of the global network properties, the local and global efficiency of the baseline scan were significantly lower compared to the follow-up scan. Moreover, the annual rate of changes in local and global efficiency showed a positive and negative quadratic correlation with the baseline age, respectively; both curvilinear correlations peaked at approximately the age of 50. In the analysis of the regional nodal properties, significant negative correlations between the annual rate of changes in nodal strength and the baseline age were found in the brain regions primarily involved in the visual and motor/ control systems, whereas significant positive quadratic correlations were found in the brain regions predominately associated with the default-mode, attention, and memory systems. The results of the longitudinal study are consistent with the findings of our previous cross-sectional study: the structural brain networks develop into a fast distribution from young to middle age (approximately 50 years old and eventually became a fast localization in the old age. Our findings elucidate the network topology of structural brain networks and its longitudinal changes, thus enhancing the understanding of the underlying physiology of normal aging in the human brain.

Leadership in transformation: a longitudinal study in a nursing organization.

Science.gov (United States)

Viitala, Riitta

2014-01-01

Not only does leadership produce changes, but those changes produce leadership in organisations. The purpose of this paper is to present a theoretical and empirical analysis of the transformation of leadership at two different historical points in a health care organisation. It leans on the perspective of social constructionism, drawing especially from the ideas of Berger and Luckmann (1966). The paper seeks to improve understanding of how leaders themselves construct leadership in relation to organisational change. The empirical material was gathered in a longitudinal case study in a nursing organisation in two different historical and situational points. It consists of written narratives produced by nurse leaders that are analysed by applying discourse analysis. The empirical study revealed that the constructions of leadership were dramatically different at the two different historical and situational points. Leadership showed up as a complex, fragile and changing phenomenon, which fluctuates along with the other organisational changes. The results signal the importance of agency in leadership and the central role of "significant others". The paper questions the traditional categorisation and labelling of leadership as well as the cross-sectional studies in understanding leadership transformation. Its originality relates to the longitudinal perspective on transformation of leadership in the context of a health care organisation.

The effects of childbirth on women’s activity change and occupational mobility in Europe: Evidence from the European Community Household Panel.

OpenAIRE

Chzhen, Yekaterina

2009-01-01

This paper uses comparable longitudinal data from the European Community Household Panel from 1994 to 2001 to examine the effects of recent childbirth on the relative risks of switching to part-time, inactivity or unemployment for full-time women, as well as the effect of switching from full-time time to part-time work on the risk of occupational downgrading, in 13 European countries. Once important human capital and workplace characteristics are controlled for, full-time female workers who g...

Development of Electrostatically Clean Solar Array Panels

Science.gov (United States)

Stern, Theodore G.

2000-01-01

Certain missions require Electrostatically Clean Solar Array (ECSA) panels to establish a favorable environment for the operation of sensitive scientific instruments. The objective of this program was to demonstrate the feasibility of an ECSA panel that minimizes panel surface potential below 100mV in LEO and GEO charged particle environments, prevents exposure of solar cell voltage and panel insulating surfaces to the ambient environment, and provides an equipotential, grounded structure surrounding the entire panel. An ECSA panel design was developed that uses a Front Side Aperture-Shield (FSA) that covers all inter-cell areas with a single graphite composite laminate, composite edge clips for connecting the FSA to the panel substrate, and built-in tabs that interconnect the FSA to conductive coated coverglasses using a conductive adhesive. Analysis indicated the ability of the design to meet the ECSA requirements. Qualification coupons and a 0.5m x 0.5m prototype panel were fabricated and tested for photovoltaic performance and electrical grounding before and after exposure to acoustic and thermal cycling environments. The results show the feasibility of achieving electrostatic cleanliness with a small penalty in mass, photovoltaic performance and cost, with a design is structurally robust and compatible with a wide range of current solar panel technologies.

Solar panel foundation device

Energy Technology Data Exchange (ETDEWEB)

Hawley, W.W.

1983-03-29

A transportable solar panel foundation device which has a bottom member, at least one upstanding side member, and an essentially open top. The side members are angled to permit nesting of a plurality of the foundation devices, and reinforcement pads are carried by the foundation device to support legs for one or more solar panels.

Active structural acoustic control of noise transmission through double panel systems

Science.gov (United States)

Carneal, James P.; Fuller, Chris R.

1995-04-01

A preliminary parametric study of active control of sound transmission through double panel systems has been experimentally performed. The technique used is the active structural acoustic control (ASAC) approach where control inputs, in the form of piezoelectric actuators, were applied to the structure while the radiated pressure field was minimized. Results indicate the application of control inputs to the radiating panel resulted in greater transmission loss due to its direct effect on the nature of the structural-acoustic coupling between the radiating panel and the receiving chamber. Increased control performance was seen in a double panel system consisting of a stiffer radiating panel with a lower modal density. As expected, more effective control of a radiating panel excited on-resonance is achieved over one excited off-resonance. In general, the results validate the ASAC approach for double panel systems and demonstrate that it is possible to take advantage of double panel behavior to enhance control performance, although it is clear that further research must be done to understand the physics involved.

Callosal tissue loss parallels subtle decline in psychomotor speed. A longitudinal quantitative MRI study. The LADIS Study

NARCIS (Netherlands)

Jokinen, H.; Frederiksen, K.S.; Garde, E.; Skimminge, A.; Siebner, H.; Waldemar, G.; Ylikoski, R.; Madureira, S.; Verdelho, A.; van Straaten, E.C.W.; Barkhof, F.; Fazekas, F.; Schmidt, R.; Pantoni, L.; Inzitari, D.; Erkinjuntti, T.

2012-01-01

Cross-sectional studies have suggested that corpus callosum (CC) atrophy is related to impairment in global cognitive function, mental speed, and executive functions in the elderly. Longitudinal studies confirming these findings have been lacking. We investigated whether CC tissue loss is associated

Law Panel in action.

Science.gov (United States)

Odulana, J

In September 1976 the Africa Regional Council (ARC) of IPPF created a Law Panel to 1) advise the ARC on the emphasis of laws and parenthood programs in the region, 2) investigate legal obstacles to family planning and ways of removing them, 3) institute a monitoring service on laws and court decisions affecting planned parenthood, and 4) prepare a list of lawyers and legal reformers by country. The panel has 1) recommended adoption of an IPPF Central Medical Committee and Central Law Panel statement on sterilization, adolescent fertility control, and the use of medical and auxiliary personnel in family planning services with guidelines for Africa; 2) appointed National Legal Correspondents to carry on the monitoring service mentioned above in 18 countries; and 3) discussed solutions to problems in delivering family planning services with family planning associations in Tanzania, Zambia, Mauritius, Madagascar, and Kenya. Laws governing family planning education and services, marriage, divorce, and maternity benefits in these countries are summarized. In 1978 the panel will hold 2 workshops on law and the status of women.

Longitudinal Stability Study for the FACET-II e⁺ Damping Ring

Energy Technology Data Exchange (ETDEWEB)

Bane, Karl [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2016-11-29

This is an initial study of the longitudinal, single-bunch stability in the proposed FACET-II e⁺ damping ring. It is preliminary because, at present, only a few specific features of the vacuum chamber are known.

PVT Panels. Fully renewable and competitive

International Nuclear Information System (INIS)

Bakker, M.; Strootman, K.J.; Jong, M.J.M.

2003-10-01

A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. PVT panels generate more solar energy per unit surface area than a combination of separate PV panels and solar thermal collectors, and share the aesthetic advantage of PV. After several years of research, PVT panels have been developed into a product that is now ready for market introduction. One of the most promising system concepts, consisting of 25 m 2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS, and has been found to be able to fully cover both the building related electricity and heat consumption, while keeping the long-term average ground temperature constant. The cost and payback time of such a system have been determined; it has been found that the payback time of this system is approximately two-thirds of the payback time of an identical system but with 21 m 2 of PV panels and 4 m 2 of solar thermal collectors. Finally, by looking at the expected growth in the PV and solar thermal collector market, the market potential for for PVT panels has been found to be very large

Change in University Teachers' Elearning Beliefs and Practices: A Longitudinal Study

Science.gov (United States)

Scott, Karen M.

2016-01-01

Little longitudinal research has examined change in university teachers' elearning beliefs and practices after their initial experience with elearning. This study addresses this gap by focusing on six teachers who developed and implemented an elearning resource, and the changes they made to the resource and its implementation over two years. A…

Application of Prefabricated Panels for the Energy Retrofit of Portuguese Residential Buildings Facades: A Case Study

Directory of Open Access Journals (Sweden)

Sousa J.

2013-09-01

Full Text Available This article aims to evaluate the potential application of prefabricated panels in energy retrofit of facades in the Portuguese building stock. The fundamentals of this study were part of Annex 50, which was an international ECBCS IEA project, with the purpose of developing an innovative concept of building renovation for the most representative buildings based on prefabricated systems. To analyze the potential application of energy retrofit using prefabricated panels, was important to know the reality of the existing building stock and its morphology. To know the reality of the building stock, an analysis was done based on the existing statistical data and to find the most representative residential buildings, target of the study, three criteria were defined: buildings built before 1990, with 2 to 6 floors and with renovation needs in the exterior envelope.

Socioeconomic gradients of cardiovascular risk factors in China and India: results from the China health and retirement longitudinal study and longitudinal aging study in India.

Science.gov (United States)

Hu, Peifeng; Wang, Serena; Lee, Jinkook

2017-09-01

Cardiovascular disease has become a major public health challenge in developing countries. The goal of this study is to compare socioeconomic status (SES) gradients of cardiovascular risk factors (CVRF) both within and between China and India. We used multivariable logistic regression models to examine the associations between SES and CVRF, using data from the China health and retirement longitudinal study and the longitudinal aging study in India. The results showed that, compared to illiteracy, the odds ratios of completing junior high school for high-risk waist circumference were 4.99 (95% confidence interval: 1.77-14.06) among Indian men, 3.42 (95% confidence interval: 1.66-7.05) among Indian women, but 0.74 (95% confidence interval: 0.59-0.92) among Chinese women. Similar patterns were observed between educational attainment and high-risk body mass index, and between education and hypertension, based on self-reported physician diagnosis and direct blood pressure measurements. SES is associated with CVRF in both China and India. However, this relationship showed opposite patterns across two countries, suggesting that this association is not fixed, but is subjective to underlying causal pathways, such as patterns of risky health behaviors and different social and health policies.

Barrier pillar between production panels in coal mine

Energy Technology Data Exchange (ETDEWEB)

Zingano, Andre Cezar; Koppe, Jair Carlos; Costa, Joao Felipe C.L. [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

2007-07-01

The function of the barrier pillar is to protect the mining panel in activity from the abutment load of adjacent mining panels that were mined. In the case of underground mines in Santa Catarina State, the barrier pillar has functioned to protect the main entries of the mine against pillar failure from old mining panels. The objective of this paper is to verify the application of the empirical method to design barrier pillars as proposed by Peng (1986), using numerical simulation following the mining geometry of the coal mines in Santa Catarina State. Two-dimensional numerical models were built taking into account the geometry of the main entries and mining panels for different overburden thickness, and considering the geomechanical properties for the rock mass that forms the roof-pillar-floor system for the Bonito coal vein. The results of the simulations showed that the empirical method to determine the barrier pillar width is valid for the studied coal vein and considered mine geometry. Neither did the pillar at the main entry become overstressed due to adjacent mine panels, nor did the roof present any failure due to stress redistribution. 9 refs., 6 figs., 5 tabs.

Experimental and theoretical study of the operation of longitudinal sidewalls in reinforced concrete superstructures

Science.gov (United States)

Bokarev, Sergey; Efimov, Stefan

2017-11-01

In the present article, we report results of a laboratory experimental study of reinforced-concrete superstructure fragments with extended longitudinal boxing sidewalls. The study included laboratory tests and numerical experiments performed using a finite element model of fragments generated in specialized simulation software. The distribution of horizontal pressures over the height of longitudinal boxing sidewalls, the dependence of the bending moment in the root section of the sidewalls on the ballast-bed thickness under sleepers, and some other characteristics were examined. The results of the experimental and theoretical study have shown a good convergence of obtained data to each other and to the data obtained by an improved engineering calculation procedure proposed by the present authors.

The influence of chronic health problems on work ability and productivity at work : a longitudinal study among older employees

NARCIS (Netherlands)

Leijten, F.R.M.; Heuvel, S.G. van den; Ybema, J.F.; Beek, A.J. van der; Robroek, S.J.W.; Burdorf, A.

2014-01-01

Objectives This study aimed to assess the influence of chronic health problems on work ability and productivity at work among older employees using different methodological approaches in the analysis of longitudinal studies. Methods Data from employees, aged 45–64, of the longitudinal Study on

The influence of chronic health problems on work ability and productivity at work: A longitudinal study among older employees

NARCIS (Netherlands)

Leijten, F.R.M.; van den Heuvel, S.G.; Ybema, Jan Fekke; van der Beek, A.J.; Robroek, S.J.W.; Burdorf, A.

2014-01-01

Objectives This study aimed to assess the influence of chronic health problems on work ability and productivity at work among older employees using different methodological approaches in the analysis of longitudinal studies. Methods Data from employees, aged 45-64, of the longitudinal Study on

The influence of chronic health problems on work ability and productivity at work: a longitudinal study among older employees

NARCIS (Netherlands)

Leijten, F.R.M.; van den Heuvel, S.G.; Ybema, J.F.; van der Beek, A.J.; Robroek, S.J.W.; Burdorf, A.

2014-01-01

Objectives This study aimed to assess the influence of chronic health problems on work ability and productivity at work among older employees using different methodological approaches in the analysis of longitudinal studies. Methods Data from employees, aged 45-64, of the longitudinal Study on

Relation between birth weight and blood pressure: longitudinal study of infants and children

NARCIS (Netherlands)

L.J. Launer (Lenore); D.E. Grobbee (Diederick); A. Hofman (Albert)

1993-01-01

textabstractOBJECTIVE--To study the relation between birth weight and systolic blood pressure in infancy and early childhood. DESIGN--Longitudinal study of infants from birth to 4 years of age. SETTING--A middle class community in the Netherlands. PARTICIPANTS--476

A Longitudinal Study of Child Siblings and Theory of Mind Development

Science.gov (United States)

McAlister, Anna; Peterson, Candida

2007-01-01

This study tested a sample of 63 children twice in a longitudinal design over 14 months to examine their theory-of-mind (ToM) understanding in relation to their number of child-aged siblings (1-12 years). Age-appropriate batteries of ToM tests emphasising false belief were given at the start of the study, when children had a mean age of 4-2…

Experimental study of hydronic panels system and its environment

Energy Technology Data Exchange (ETDEWEB)

Diaz, Nestor Fonseca [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

2011-01-15

An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure. (author)

Experimental study of hydronic panels system and its environment

Energy Technology Data Exchange (ETDEWEB)

Fonseca Diaz, Nestor, E-mail: nestorfonseca5@hotmail.co [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

2011-01-15

An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure.

Damage Tolerance of Pre-Stressed Composite Panels Under Impact Loads

Science.gov (United States)

Johnson, Alastair F.; Toso-Pentecôte, Nathalie; Schueler, Dominik

2014-02-01

An experimental test campaign studied the structural integrity of carbon fibre/epoxy panels preloaded in tension or compression then subjected to gas gun impact tests causing significant damage. The test programme used representative composite aircraft fuselage panels composed of aerospace carbon fibre toughened epoxy prepreg laminates. Preload levels in tension were representative of design limit loads for fuselage panels of this size, and maximum compression preloads were in the post-buckle region. Two main impact scenarios were considered: notch damage from a 12 mm steel cube projectile, at velocities in the range 93-136 m/s; blunt impact damage from 25 mm diameter glass balls, at velocities 64-86 m/s. The combined influence of preload and impact damage on panel residual strengths was measured and results analysed in the context of damage tolerance requirements for composite aircraft panels. The tests showed structural integrity well above design limit loads for composite panels preloaded in tension and compression with visible notch impact damage from hard body impact tests. However, blunt impact tests on buckled compression loaded panels caused large delamination damage regions which lowered plate bending stiffness and reduced significantly compression strengths in buckling.

Longitudinal plasma metabolic profiles, infant feeding, and islet autoimmunity in the MIDIA study

DEFF Research Database (Denmark)

Jørgenrud, Benedicte; Stene, Lars C; Tapia, German

2017-01-01

Aims: The aim of this study was to investigate the longitudinal plasma metabolic profiles in healthy infants and the potential association with breastfeeding duration and islet autoantibodies predictive of type 1 diabetes. Method: Up to four longitudinal plasma samples from age 3 months from case......, and lower levels of methionine and 3,4-dihydroxybutyric acid at 3 months of age. Conclusions: Plasma levels of several small, polar metabolites changed with age during early childhood, independent of later islet autoimmunity status and sex. Breastfeeding was associated with higher levels of branched......-chain amino acids, and lower levels of methionine and 3,4-dihydroxybutyric acid....

Panel Flutter Emulation Using a Few Concentrated Forces

Science.gov (United States)

Dhital, Kailash; Han, Jae-Hung

2018-04-01

The objective of this paper is to study the feasibility of panel flutter emulation using a few concentrated forces. The concentrated forces are considered to be equivalent to aerodynamic forces. The equivalence is carried out using surface spline method and principle of virtual work. The structural modeling of the plate is based on the classical plate theory and the aerodynamic modeling is based on the piston theory. The present approach differs from the linear panel flutter analysis in scheming the modal aerodynamics forces with unchanged structural properties. The solutions for the flutter problem are obtained numerically using the standard eigenvalue procedure. A few concentrated forces were considered with an optimization effort to decide their optimal locations. The optimization process is based on minimizing the error between the flutter bounds from emulated and linear flutter analysis method. The emulated flutter results for the square plate of four different boundary conditions using six concentrated forces are obtained with minimal error to the reference value. The results demonstrated the workability and viability of using concentrated forces in emulating real panel flutter. In addition, the paper includes the parametric studies of linear panel flutter whose proper literatures are not available.

Job Demands and Resources as Antecedents of Work Engagement: A Longitudinal Study

Science.gov (United States)

Mauno, Saija; Kinnunen, Ulla; Ruokolainen, Mervi

2007-01-01

By utilizing a 2-year longitudinal design, the present study investigated the experience of work engagement and its antecedents among Finnish health care personnel (n = 409). The data were collected by questionnaires in 2003 (Time 1) and in 2005 (Time 2). The study showed that work engagement--especially vigor and dedication--was relatively…

Media Exposure, Aggression and Prosocial Behavior during Early Childhood: A Longitudinal Study

Science.gov (United States)

Ostrov, Jamie M.; Gentile, Douglas A.; Crick, Nicki R.

2006-01-01

Preschool children (N = 78) enrolled in multi-informant, multi-method longitudinal study were participants in a study designed to investigate the role of media exposure (i.e., violent and educational) on concurrent and future aggressive and prosocial behavior. Specifically, the amount of media exposure and the nature of the content was used to…