Ballistic nanofriction

Sliding parts in nanosystems such as Nano ElectroMechanical Systems (NEMS) and nanomotors, increasingly involve large speeds, and rotations as well as translations of the moving surfaces; yet, the physics of high speed nanoscale friction is so far unexplored. Here, by simulating the motion of drifting and of kicked Au clusters on graphite - a workhorse system of experimental relevance -- we demonstrate and characterize a novel "ballistic" friction regime at high speed, separate from drift at low speed. The temperature dependence of the cluster slip distance and time, measuring friction, is opposite in these two regimes, consistent with theory. Crucial to both regimes is the interplay of rotations and translations, shown to be correlated in slow drift but anticorrelated in fast sliding. Despite these differences, we find the velocity dependence of ballistic friction to be, like drift, viscous

State of the Art on Prediction of Concrete Pumping

Large scale constructions needs to estimate a possibility for pumping concrete. In this paper, the state of the art on prediction of concrete pumping including analytical and experimental works is presented. The existing methods to measure the rheological properties of slip layer (or called lubricating layer) are first introduced. Second, based on the rheological properties of slip layer and parent concrete, models to predict concrete pumping (flow rate, pumping pressure, and pumpable distance) are explained. Third, influencing factors on concrete pumping are discussed with the test results of various concrete mixes. Finally, future need for research on concrete pumping is suggested.ope

Channel Characteristics of MIMO-WLAN Communications at 60GHz for Various Corridors

[[abstract]]A comparison of 4 × 4 multiple-input multiple-output wireless local area network wireless communication characteristics for six different geometrical shapes is investigated. These six shapes include the straight shape corridor with rectangular cross section, the straight shape corridor with arched cross section, the curved shape corridor with rectangular cross section, the curved shape corridor with arched cross section, the L-shape corridor, and the T-shape corridor. The impulse responses of these corridors are computed by applying shooting and bouncing ray/image (SBR/Image) techniques along with inverse Fourier transform. By using the impulse response of these multipath channels, the mean excess delay, root mean square (RMS) delay spread for these six corridors can be obtained. Numerical results show that the capacity for the rectangular cross section corridors is smaller than those for the arched cross section corridors regardless of the shapes. And the RMS delay spreads for the T-and the L-shape corridors are greater than the other corridors.[[notice]]補正完畢[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]紙本[[booktype]]電子

Factors related with the university degree selection in Spanish public university system. An structural equation model analysis

The final publication is available at Springer via http://dx.doi.org/10.1007/s11135-014-0008-9Students take into account different factors in their choice of university studies and college. Some are global, as the quality of the degree (ratio available places/firstchoice places in, cut-off grade, etc.), and others are subjective factors (e.g.: my friends are also taking this degree). In this work we present a partial multivariate model that takes into account the weight of the different variables shown by different works linked to this decision. We have studied three samples (n = 372 from the Universidad Pablo de Olavide; n = 2,244 from the Universitat Politécnica de Valencia, and n = 543 from the Universitat de Barcelona) from several degrees in the 2010 2011 and 2011 2012 academic years, all of them new students, coming from high school, and who had choosen these universities as first choice. The global effect shows that the structural model fits reasonably well in the three universities studied. Similarly, university and specialty models show different intensity effects, and we found that, in the case of Universitat Politécnica de Valencia (UPV) and Universitat de Barcelona (UB), they show higher intensity than in Universidad Pablo de Olavide (UPO). This makes us think that in most urban universities with a clear and regular offer of degrees (engineering in the case of UPV, and Health and Social Sciences in the case of UB), personal and social factors are more important than in the case of universities, as is the case of UPO, with an offer and dimension not yet completely defined.Guàrdia Olmos, J.; Peró Cebollero, M.; Hervás Jorge, A.; Capilla Lladró, R.; Soriano Jiménez, PP.; Porras Yañez, M. (2014). Factors related with the university degree selection in Spanish public university system. An structural equation model analysis. Quality and Quantity. 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Anuario de Psicologia 42(1), 87–104 (2012)Guerra, C., & Rueda, E.M.: Estudio longitudinal de los jóvenes en el tránsito de la enseñza secundaria a la universidad: orientación, expectativas, toma de decisiones y acogida de los nuevos estudiantes en la universidad. Dirección General de Universidades. Estudios y Análisis (2005)Hu, L., Bentler, P.M.: Cutoff criteria for fit indexes in covariance structure analysis: conventional criteria versus new alternatives. Struct. Equ. Model. 6, 1–55 (1999)Huang, Sh, Fang, N.: Predicting student academic performance in an enginnering dynamics course: a comparison for four types of predictive mathematical models. Comput. Educ. 61, 133–145 (2013)Leppel, K., Williams, M.L., Waldauer, C.: The impact of parental occupation and socioeconomic status on choice of college major. J. Fam. Econ. Issues 22(4), 373–394 (2001)Maringe, F.: University and course choice Implications for positioning, recruitment and marketing. Int. J. Educ. Manage. 20(6), 466–479 (2006)Muñiz, J.: Utilización de los test. En J. Muñiz, A.M. Fidalgo, E. García-Cueto, R. Martínez y R. Moreno (Eds.). Análisis de los ítems, (pp. 133–172). Madrid: La Muralla, S.A (2005)Murphy, P.E., McGarrity, R.A.: Marketing universities: a survey of student recruitment activities. Coll. Univ. 53(3), 249–261 (1978)Ory, D.T., Mokhtarian, P.L.: The impact of non-normality, sample size and estimation technique on goodness-of-fit measures in structural equation modeling: evidence from ten empirical models of travel behavior. Qual. Q. 44(3), 427–445 (2010)Palomo, J., Dunson, D.B., Bollen, K.: Bayesian structural equation modeling. In: Lee, S.Y. (ed.) Handbook of Latent Variable and Related Models, pp. 163–179. Elsevier, New York (2007)Perna, L.W., Titus, M.A.: Understanding differences in the choice of college attended: the role of state public policies. Rev. High. Educ. 27(4), 501–525 (2004)Poon, W.Y., Lee, S.Y.: A Distribution Free Approach for Analysis of Two-level Structural Equation Model. Elsevier, New York (1994)Price, I., Matzdorf, F., Smith, L., Agahi, H.: The impact of facilities on student choice of university. Facilities 21(10), 212–222 (2003)Raymond, S.: Predicting academic succes of first-year engineering students from standardized test scores and psychological variables. Int. J. Eng. Educ. 17(1), 75–80 (2001)Turner, C.S.V., Thompson, J.R.: Socializing women doctoral students: minority and majority experiences. Rev. High. Educ. 6, 232–241 (1993)Veenstra, C.P., Dey, E.L., Herrin, G.D.: Is modeling of freshman engineering succes different from modeling of non-engineering succes? J. Eng. Educ. 97, 467–479 (2008)Yurtseven, T.: How does the image of engineering affect student recruitment and retention? A perspective from the USA. Glob. J. Eng. Educ. 6(2), 267 (2002

The study on the outsourcing of Taiwan's hospitals: a questionnaire survey research

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to assess the outsourcing situation in Taiwanese hospitals and compares the differences in hospital ownership and in accreditation levels.</p> <p>Methods</p> <p>This research combined two kinds of methods: a questionnaire survey and the in-depth interview to two CEOs of the sample hospitals. One hospital is not-for-profit, while the other is a public hospital and the research samples are from the hospital data from Taiwan's 2005 to 2007 Department of Health qualifying lists of hospital accreditation. The returned questionnaires were analyzed with STATISTICA^®7.1 version software.</p> <p>Results</p> <p>The results for non-medical items showed medical waste and common trash both have the highest rate (94.6 percent) of being outsourced. The gift store (75 percent) and linen (73 percent) follow close behind, while the lowest rate of outsourcing is in utility maintenance (13.5 percent). For medical items, the highest rate of outsourcing is in the ambulance units (51.4 percent), while the hemodialysis center follows close behind with a rate of 50 percent. For departments of nutrition, pharmacy, and nursing however, the outsourcing rate is lower than 3 percent. This shows that Taiwan's hospitals are still conservative in their willingness to outsource for medical items. The results of the satisfaction paired t-test show that the non-medical items have a higher score than the medical items. The factor analysis showed the three significant factors in of non medical items' outsourcing are "performance", "finance", and "human resource". For medical items, the two factors are "operation" and satisfaction". To further exam the factor validity and reliability of the satisfaction model, a confirmative factor analysis (CFA) was conducted using structure equation modeling (SEM) method and found the model fitting well.</p> <p>Conclusion</p> <p>Hospitals, especially for public hospitals, can get benefits from outsourcing to revive the full-time-equivalent and human resource limitation.</p

Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial

IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved

Bayesian shrinkage mapping of quantitative trait loci in variance component models

<p>Abstract</p> <p>Background</p> <p>In this article, I propose a model-selection-free method to map multiple quantitative trait loci (QTL) in variance component model, which is useful in outbred populations. The new method can estimate the variance of zero-effect QTL infinitely to zero, but nearly unbiased for non-zero-effect QTL. It is analogous to Xu's Bayesian shrinkage estimation method, but his method is based on allelic substitution model, while the new method is based on the variance component models.</p> <p>Results</p> <p>Extensive simulation experiments were conducted to investigate the performance of the proposed method. The results showed that the proposed method was efficient in mapping multiple QTL simultaneously, and moreover it was more competitive than the reversible jump MCMC (RJMCMC) method and may even out-perform it.</p> <p>Conclusions</p> <p>The newly developed Bayesian shrinkage method is very efficient and powerful for mapping multiple QTL in outbred populations.</p

Comparisons of the factor structure and measurement invariance of the Spence children’s anxiety scale - parent version in children with autism spectrum disorder and typically developing anxious children

The Spence Children’s Anxiety Scale - Parent version (SCAS-P) is often used to assess anxiety in children with autism spectrum disorder (ASD), however, little is known about the validity of the tool in this population. The aim of this study was to determine whether the SCAS-P has the same factorial validity in a sample of young people with ASD (n=285), compared to a sample of typically developing young people with anxiety disorders (n=224). Poor model fit with all of the six hypothesised models precluded invariance testing. Exploratory factor analysis indicated that different anxiety phenomenology characterises the two samples. The findings suggest that cross-group comparisons between ASD and anxious samples based on the SCAS-P scores may not always be appropriat