86,512 research outputs found
Cold-Curing Structural Epoxy Resins: Analysis of the Curing Reaction as a Function of Curing Time and Thickness
No full textThe curing reaction of a commercial cold-curing structural epoxy resin, specifically formulated for civil engineering applications, was analyzed by thermal analysis as a function of the curing time and the sample thickness. Original and remarkable results regarding the effects of curing time on the glass transition temperature and on the residual heat of reaction of the cold-cured epoxy were obtained. The influence of the sample thickness on the curing reaction of the cold-cured resin was also deeply investigated. A highly exothermal reaction, based on a self-activated frontal polymerization reaction, was supposed and verified trough a suitable temperature signal acquisition system, specifically realized for this measurement. This is one of the first studies carried out on the curing behavior of these peculiar cold-cured epoxy resins as a function of curing time and thickness
The aspect ratio of epoxy matrix nanocomposites reinforced with graphene stacks
No full textThe improvement of physical and mechanical properties
of nanofilled matrices significantly depends on the
average size of dispersed fillers. In particular, the aspect
ratio of lamellar nanofillers, such as graphene
stacks, results from a combination of both filler morphology
and processing techniques. In this study,
nanocomposites were obtained dispersing three different
graphene precursors in an epoxy resin: expanded
graphite, commercial graphene nanoplatelets, and natural
graphite. Epoxy matrix nanocomposites reinforced
with graphene stacks, ranging from 1 wt% to 3 wt%
were prepared and characterized. The structural, mechanical,
and thermal properties of expanded graphitebased
nanocomposites, as well as the rheological
properties of liquid resin/filler suspensions, were studied
and compared with those of the unfilled epoxy matrix
and of the matrix filled with natural graphite and
commercial nanoplatelets. The comparison of mechanical
and rheological properties with simple mathematical
models indicated that the aspect ratio of expanded
graphite is in the order of 1000, i.e., a dispersion of
nanoscale graphene stacks was obtained. This result
suggests that the measurement of engineering properties
of nanocomposites not only represents an objective
but can also provide information about the average
degree of dispersion
Cross-cultural perspective of driving style in young adults: Psychometric evaluation through the analysis of the Multidimensional Driving Style Inventory.
No full textSelf-evaluating methods are frequently used to identify driving styles. Among others, one of the most commonly used questionnaires is the Multidimensional Driving Style Inventory (MDSI), developed for the Israeli population. Because of the extensive use of the questionnaire, the present paper aims to validate an Italian version and to confirm the 8-factor structure of the original one, i.e, dissociative, anxious, risky, angry, highvelocity, distress-reduction, patient, and careful driving style. The Italian version of the MDSI was filled out by 561 Italian drivers, who had a driving license for at least 1 year. A confirmatory factorial analysis (CFA) was conducted on the 44-item of the translated questionnaire showing not so good values of the goodness of fit tests (SRMR = 0.085; RMSEA = 0.063). The total-item correlation of each scale indicated that 4 items had a low index of total-item correlation. A second CFA was conducted on the remaining 40 items: goodness fit parameters improved (SRMR = 0.0685, RMSEA = 0.0584). Previous validations of the original version of MDSI for different populations (Argentine, Romanian, Chinese, Malaysian, Butch and Belgian) showed several critical issues in confirming the original structure. In the Italian version of MDSI validated in the present paper, the original 8-factor structure was confirmed by removing the 4 items which did not properly contribute to the factors. The results not only confirmed the usefulness of the MDSI in assessing driving style but they also indicated that the concept of driving style is considered in the same way in Italy and Israel, even though traffic rules are different. The latter consideration raises interesting questions for future research concerning cross-cultural comparisons of driving behavior in different countries
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Real-time coaching programs for Manage-How-You-Drive insurance schemes: Analysis of retention after feedback removal
No full textManage-How-You-Drive (MHYD) is an innovative usage-based insurance scheme where drivers are charged premiums based on their safety performance, incorporating real-time coaching programs to provide drivers with contingent feedback, nudging them to drive more safely. As limited research exists on these novel schemes, this study aims to confirm their effectiveness, by expanding the sample size and the scope of analysis from a previous study by the authors, and to specifically focus on the retention of improved behavior and the impact of driver characteristics and feedback types on retention. A driving simulator experiment involving 100 drivers was used to test four feedback systems, with different modality (auditory vs. visual) and valence (i.e., pleasantness of the feedback: positive vs. negative), based on the occurrence of Elevated Gravitational-Force Events (EGFEs, i.e., harsh acceleration/deceleration events). Drivers completed three trials, spaced four weeks apart. The first trial served as a baseline without any feedback, in the second trial one of the feedback systems was presented, and the third trial had no feedback. Program effectiveness and retention were assessed based on EGFE occurrences and mean acceleration/deceleration. Its indirect influence on speeding, tailgating, and lateral control was investigated to assess potential additional enduring effects on safety performance. Drivers, especially those identified as “aggressive” during the baseline trial, not only significantly benefited from using the coaching program, but were also able to at least partially retain such benefits in terms of acceleration/deceleration, speeding and tailgating, irrespective of feedback type. These findings highlight the potential practical advantages of MHYD real-time coaching systems for road safety
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Visual Feedback Effectiveness in Reducing Over Speeding of Moped-Riders
No full textThe use of assistance systems aimed at reducing road fatalities is spreading, especially for car drivers, but less effort has been devoted to developing and testing similar systems for powered two-wheelers (PTWs). Considering that over speeding represents one of the main causal factors in road crashes and that riders are more vulnerable than drivers, in the present study we investigated the effectiveness of an assistance system which signaled speed limit violations during a simulated moped-driving task, in optimal and poor visibility conditions. Participants performed four conditions of simulated riding: one baseline condition without Feedback, one Fog condition in which visual feedback was provided so as to indicate to the participants when a speed limit (lower than that indicated by the traffic signals) was exceeded, and two post-Feedback conditions with and without Fog, respectively, in which no feedback was delivered. Results showed that participants make fewer speeding violations when the feedback is not provided, after 1 month, and regardless of the visibility condition. Finally, the feedback has been proven effective in reducing speed violations in participants with an aggressive riding style, as measured in the baseline session.POR FSE 2014-2020
2105-56-11-2018Generali Italia S.p.aSpanish State Research Agency
RYC-2015-1748
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