Ettringite and thaumasite: A chemical route for their removal from cementious artefacts   总被引：1，自引：0，他引：1  

Enrico Ciliberto  Salvatore Ioppolo  Fabio Manuella   《Journal of Cultural Heritage》2008,9(1):30-37

The present paper reports a new method for converting ettringite and thaumasite in non-expansible and insoluble phases, for its application in the restoration of concrete artefacts subjected to deterioration through sulphate attack. The salts were synthesized by different processes and, after characterization by means of XRD, FT-IR and optical microscopy, were treated with a series of chemicals in order to induce their decomposition. In particular, different solutions containing barium nitrate, barium hydroxide and ammonium oxalate were used to achieve the complete transformation of both phases in barite, witherite, scarbroite and whewellite. Barium hydroxide seemed to be the most appropriate reactant because the others could give rise to efflorescence within the pores of the mortars by leaving free nitrate or sulphate ions inside the materials. The experimental technique was also tested on two concrete samples collected from the bell-tower of St. Nicholas’ Cathedral in Nicosia (Sicily) with encouraging results.  相似文献   

Educational planning and administration in Latin America     

Fabio M. Bustos 《Prospects》1991,21(1):43-50

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Artificial moral agents: moral mentors or sensible tools?     

Fabio Fossa 《Ethics and Information Technology》2018,20(2):115-126

The aim of this paper is to offer an analysis of the notion of artificial moral agent (AMA) and of its impact on human beings’ self-understanding as moral agents. Firstly, I introduce the topic by presenting what I call the Continuity Approach. Its main claim holds that AMAs and human moral agents exhibit no significant qualitative difference and, therefore, should be considered homogeneous entities. Secondly, I focus on the consequences this approach leads to. In order to do this I take into consideration the work of Bostrom and Dietrich, who have radically assumed this viewpoint and thoroughly explored its implications. Thirdly, I present an alternative approach to AMAs—the Discontinuity Approach—which underscores an essential difference between human moral agents and AMAs by tackling the matter from another angle. In this section I concentrate on the work of Johnson and Bryson and I highlight the link between their claims and Heidegger’s and Jonas’s suggestions concerning the relationship between human beings and technological products. In conclusion I argue that, although the Continuity Approach turns out to be a necessary postulate to the machine ethics project, the Discontinuity Approach highlights a relevant distinction between AMAs and human moral agents. On this account, the Discontinuity Approach generates a clearer understanding of what AMAs are, of how we should face the moral issues they pose, and, finally, of the difference that separates machine ethics from moral philosophy.  相似文献   

Validity of an ultra-wideband local positioning system to measure locomotion in indoor sports     

F. R. Serpiello  W. G. Hopkins  S. Barnes  J. Tavrou  G. M. Duthie  R. J. Aughey 《Journal of sports sciences》2018,36(15):1727-1733

The validity of an Ultra-wideband (UWB) positioning system was investigated during linear and change-of-direction (COD) running drills. Six recreationally-active men performed ten repetitions of four activities (walking, jogging, maximal acceleration, and 45º COD) on an indoor court. Activities were repeated twice, in the centre of the court and on the side. Participants wore a receiver tag (Clearsky T6, Catapult Sports) and two reflective markers placed on the tag to allow for comparisons with the criterion system (Vicon). Distance, mean and peak velocity, acceleration, and deceleration were assessed. Validity was assessed via percentage least-square means difference (Clearsky-Vicon) with 90% confidence interval and magnitude-based inference; typical error was expressed as within-subject standard deviation. The mean differences for distance, mean/peak speed, and mean/peak accelerations in the linear drills were in the range of 0.2–12%, with typical errors between 1.2 and 9.3%. Mean and peak deceleration had larger differences and errors between systems. In the COD drill, moderate-to-large differences were detected for the activity performed in the centre of the court, increasing to large/very large on the side. When filtered and smoothed following a similar process, the UWB-based positioning system had acceptable validity, compared to Vicon, to assess movements representative of indoor sports.  相似文献   

Kicking Performance in Young U9 to U20 Soccer Players: Assessment of Velocity and Accuracy Simultaneously     

Luiz H. P. Vieira  Sérgio A. Cunha  Renato Moraes  Fabio A. Barbieri  Rodrigo Aquino  Lucas de P. Oliveira 《Research quarterly for exercise and sport》2018,89(2):210-220

Purpose: The purpose of this study was to compare the kicking performance of young soccer players in the U9 to U20 age groups. Method: Three hundred and sixty-six Brazilian players were evaluated on an official pitch using three-dimensional kinematics to measure (300 Hz) ball velocity (V_ball), foot velocity (V_foot), V_ball/V_foot ratio, last stride length, and distance between the support foot and the ball. Simultaneously, a two-dimensional procedure was also conducted to compute (60 Hz) the mean radial error, bivariate variable error, and accuracy. Possible age-related differences were assessed through one-way analysis of variance and magnitude-based inferences. Results: Ball velocity increased by 103% (p < .001, η² = .39) from the U11 age group (48.54 ± 8.31 km/hr) to the U20 age group (98.74 ± 16.35 km/hr). Foot velocity presented a 59% increase (p < .001, η² = .32) from the U11 age group (49.08 ± 5.16 km/hr) to U20 (78.24 ± 9.49 km/hr). This finding was due to improvement in the quality of foot–ball impact (V_ball/V_foot ratio) from U11 (0.99 ± 0.13 a.u.) to U20 (1.26 ± 0.11 a.u.; p < .001, η² = .25). Parameters such as mean radial error and accuracy appeared to be impaired during the growth spurt (U13–U15). Last stride length was correlated, low to moderately high, with V_ball in all age groups (r = .36–.79). Conclusions: In summary, we concluded that simple biomechanical parameters of kicking performance presented distinct development. These results suggest that different training strategies specific for each age group could be applied. We provide predictive equations to aid coaches in the long-term monitoring process to develop the kick in soccer or search for talented young players.  相似文献   

Preventive thermographic diagnosis of historical buildings for consolidation     

Domenica Paoletti  Dario Ambrosini  Stefano Sfarra  Fabio Bisegna 《Journal of Cultural Heritage》2013,14(2):116-121

Conserving architectural heritage usually requires a multidisciplinary approach involving a variety of professionals and organizations. Since the evaluation of the state of conservation of historical buildings using destructive techniques should be avoided to prevent the integrity of the cultural heritage, the development of non-destructive and non-contact techniques is very important. InfraRed (IR) thermography is a non-destructive powerful tool for fast and accurate building diagnostics. In the investigation of historical structures, where a restoration or conservation treatment can cause irreversible damage to the structure, it is considered to be of most importance. A campaign of thermographic surveys were conducted on a large part of the historical cultural heritage of L’Aquila and its surroundings. In this paper we present the results of the study for the Church of Santa Maria ad Cryptas (XIII century), one of the most ancient buildings in the surroundings of L’Aquila and one of the best examples of Gothic art in Abruzzo, with the aim to evaluate the correspondence between the damage induced by the earthquake and the previous thermographic results, in order to validate the effectiveness of thermography and its role in preventive diagnosis.  相似文献   

Stochastic identification and digital control of a heat exchanger: a simulation test case     

Sergio Bittanti  Fabio Romeo  Riccardo Scattolini 《Journal of The Franklin Institute》1984,318(1):29-56

In this paper, an extended simulation study is presented by which the power of modern digital identification and control methodology is tested against the nontrivial dynamics of a relatively simple yet nonelementary plant. Many critical issues which may significantly affect the success of the entire design process can be discussed along the lines of this study. The plant considered here is a liquid-saturated steam heat exchanger, where the liquid flow-rate is manipulated to regulate the outlet liquid temperature. All the numerical experiments have been conducted by digital simulation of a fairly standard nonlinear distributed parameter model.  相似文献   

Patterns of diffusion of electronics technologies: An international comparison with special reference to the Italian case     

Fabio Arcangeli 《Research Policy》1991,20(6)

The paper analyzes the patterns of diffusion of information- and microelectronics-based production technologies in Western Europe, USA and Japan. The evidence suggests asymmetries in both levels and rates of changes in their adoptions between the three areas and within Europe itself, with little support to any hypothesis of long-term convergence among these regional and national patterns.Some suggestions on why diffusion rates differ are then examined together with the likely consequences on the patterns of competitiveness.  相似文献   

The Relative Age Effect Among Female Brazilian Youth Volleyball Players     

Fabio H.A. Okazaki  Birgit Keller  Fabio E. Fontana  Jere D. Gallagher 《Research quarterly for exercise and sport》2013,84(1):135-139

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Twitter Use During TV: A Full-Season Analysis of #serviziopubblico Hashtag     

Luca Rossi  Fabio Giglietto 《广播与电子媒介杂志》2016,60(2):331-346

Several recent reports pointed out how the practice of using a “second screen” while following a television program is becoming an increasingly widespread phenomenon. When the secondary device is used to read or to comment about a watched program, most of the discussion takes place on popular social media such as Facebook and Twitter. Previous research has shown that the analysis of these contents could lead to a better understanding of the behavior of networked publics and of the structure of the show itself. Nevertheless most of the existing research is focused on the content only and focused on a single episode analysis or on big media events. Leveraging this background, this article presents instead a study focused on the relationships between content and users across an entire airing season of a TV program. Through a quantitative network analysis of the tweets produced during 25 episodes of the Italian political talks show Servizio Pubblico, we identified a small loyal group of viewers. Despite the differences in quantity of content produced, the loyal viewers do not show any sign of forming a community-like structure. We also performed a qualitative analysis of the tweets produced during one specific episode and discussed the elements of the TV show that generated the higher level of engagement on Twitter.  相似文献