Medieval and renaissance glass technology in Valdelsa (Florence). Part 1: raw materials, sands and non-vitreous finds     

U. Casellato  F. Fenzi  P. Guerriero  S. Sitran  P. A. Vigato  U. Russo  M. Galgani  M. Mendera  A. Manasse 《Journal of Cultural Heritage》2003,4(4):337-353

A significant number of archaeological finds of the 13th–16th century from the Tuscan sites of Germagnana and Gambassi in Valdelsa—FI, was studied by different physico-chemical investigations (SEM–EDS, ICP, Mössbauer spectroscopy, XRD, XRF, TG-DTA) in order to contribute to clarify the production methodology and the pre-industrial glass manufacture technology. The studied samples are mainly non-vitreous finds as production waste, refractory materials, crucibles and raw materials; also vitreous finds as frits, skims, glasses (glass masses, glass working waste and finished products) have been taken into consideration. The obtained petrographic and physico-chemical data strongly suggest that both Gambassi and Germagnana glass manufactures were strictly connected with the sources of vitrifiable materials, situated in Tuscan sand quarries. In particular a comparison between sands from the neighbouring quarries and appropriate finds of the two archaeological sites evidences that the employed vitrifiable materials possibly belong to La Casina La Cava resort. The archaeological classification, based on macroscopic observation and stratigraphic position, was compared and verified with the scientific classification of the examined finds of Germagnana and Gambassi sites based on their composition, morphology and physico-chemical properties.  相似文献   

A Follower-Centric Approach to Leadership in the Newsroom     

Manuel Goyanes  Alessandro Gentile 《Journalism Practice》2018,12(4):509-525

This article analyses leadership in the newsroom of the Spanish newspaper El País as well as its impact on the craft of journalism more generally. Through 23 in-depth interviews, we try to elucidate how the newsroom constructs its leaders (in the newsroom, what does it mean to be a leader?), paying particular attention to the main skills considered to be necessary. According to our newsroom findings, not all heads of section or editors-in-chief are leaders, a fact that questions formal authority relations and proclaims expertise and know-how as discriminatory skills. This study emphasizes that the collective recognition of a leader is not an ultimate disposition, but can vary over time: consequently leaders who do not achieve the professional requirements of the newsroom can be denied the status, despite their expertise and experience. Our findings indicate that leaders at El País are those journalists (no matter what their positions) with strong capacities and skills (fundamentally experience, expertise and creativity) to manage form (relationships) and substance (contents) in the daily work of the newsroom. In short, journalists seen as leaders combine reiterated and strong qualities and merit, graphically reflected in the texts they have published for years in the newspaper.  相似文献   

Writing     

Pietro Boscolo  Eric Espéret  Michel Fayol 《European Journal of Psychology of Education - EJPE》1991,6(2):97-98

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Global exact tracking for uncertain MIMO linear systems by output feedback sliding mode control     

Eduardo V.L. Nunes  Alessandro J. Peixoto  Tiago Roux Oliveira  Liu Hsu 《Journal of The Franklin Institute》2014

This paper presents a solution to the problem of global exact output tracking for uncertain MIMO (multiple-input–multiple-output) linear plants with non-uniform arbitrary relative degree using output feedback sliding mode control. The key idea to overcome the relative degree obstacle is to generalize our previous hybrid estimation scheme to a multivariable version by combining, through switching, a standard linear lead filter with a non-linear one based on robust exact differentiators, achieving uniform global exponential practical stability and exact tracking.  相似文献   

Temperament Dimensions in Preschool Children: Links With Cognitive and Affective Theory of Mind     

Emiddia Longobardi  Pietro Spataro  Marta D’Alessandro  Rita Cerutti 《Early education and development》2017,28(4):377-395

Research Findings: The present cross-sectional study investigated the question of whether 6 different temperament dimensions (inhibition to novelty, social orientation, motor activity, positive emotionality, negative emotionality, and attention) influenced cognitive and affective theory of mind (ToM) in 168 children (86 three/four-year-olds and 82 four/five-year-olds). Temperament was measured via a parent-report questionnaire, cognitive ToM via a classical false-belief task, and affective ToM via a comprehensive test tapping 3 levels of emotion comprehension (external, mental, and reflexive). In addition, language competence was assessed with a direct test evaluating both receptive and expressive language. The results showed that after we controlled for language ability, inhibition to novelty predicted higher levels of cognitive ToM in 4/5-year-old children. In addition, higher levels of social orientation predicted better comprehension of the external aspects of emotion in both younger and older children. Practice or Policy: Our results highlight the importance of the early identification of less sociable children, who might benefit from training interventions aimed at increasing their affective ToM abilities. At the same time, they are also consistent with previous evidence indicating that an inhibited approach to social interaction can promote false-belief understanding.  相似文献   

Interest in an expository text: How does it flow from reading to writing?   总被引：1，自引：0，他引：1  

Pietro Boscolo  Nicola AriasiLaura Del Favero  Chiara Ballarin 《Learning and Instruction》2011,21(3):467-480

This study investigated the flow of interest in a reading-to-write activity. It was hypothesized that (a) different contents in a text would stimulate different types of interest and (b) different writing tasks would impact differently students’ use of interesting text segments. Participants were 247 11th- and 12th-grade students, who were divided into 6 groups according to a 2 (interesting vs. uninteresting topic) × 3 (type of writing task) design. While reading, students rated novelty, curiosity, impressiveness, importance, and willingness to reflect on each text segment. Participants were then assigned to one of three writing tasks, namely argumentation, text designing, and composition. Results showed that concepts were regarded as important, events/activities as impressive, and evaluations as most worthy of reflection. Topic interest was explicitly expressed mainly in the argumentation condition, where increased topic interest scores after reading and writing were also found.  相似文献   

Three-dimensional kinematic analysis of the golf swing using instantaneous screw axis theory,Part 2: golf swing kinematic sequence     

Alessandro Vena  Dave Budney  Tom Forest  Jason P. Carey 《Sports Engineering》2011,13(3):125-133

A number of recent studies have measured the extent and timing of segment rotation during the golf swing. A promising technique, instantaneous screw axis (ISA) theory, could provide a better expression of segment rotation. In Part 1 of this two-part study, the objectives are to identify the ISA of the pelvis, shoulders and left arm during the downswing, compute segment angular velocity relative to that segment’s ISA and verify that ISA theory is a valid tool to analyse segment rotation during the golf swing. Results indicate that for all subjects, at least 71% of marker velocity is a result of rotation about their respective ISA, when averaging results over the duration of the downswing, confirming that motion is primarily rotational. Furthermore, ISA position and orientation of each segment approaches, on average, the expected gross axis of rotation, confirming that motion about the ISA is representative of joint motion.  相似文献   

Countermovement jump performance assessment using a wearable 3D inertial measurement unit     

Picerno P  Camomilla V  Capranica L 《Journal of sports sciences》2011,29(2):139-146

The aim of this study was to validate a wearable inertial measurement unit (IMU), containing a 3D accelerometer and gyroscope, for the estimation of countermovement jump height. The absolute vertical acceleration of the IMU positioned on the back of the participant at L5 level, compensated for trunk rotations, was used to obtain jump height by applying the equation of free-fall to the motion of the IMU. The methodology was tested on 28 participants performing five countermovement jumps each. A reference value for this quantity was obtained using stereophotogrammetry (35.4 cm, s = 4.9). Jump height scores obtained using the proposed methodology (35.9 cm, s = 5.5) presented no significant difference with respect to stereophotogrammetry (P = 0.61). A low bias of 0.6 cm confirmed the accuracy of the estimate, which also showed a high (r = 0.87) and significant (P < 0.0001) correlation with reference values. Furthermore, without compensating accelerations for trunk rotation, jump height was largely underestimated (P < 0.0001) (bias: -12.7 cm) and poorly associated (r = 0.31) with stereophotogrammetry. The results of this study show that the estimation of jump height using inertial sensors leads to accurate results when the measured accelerations are corrected for trunk rotations.  相似文献   

La Medusa by Caravaggio: characterisation of the painting technique and evaluation of the state of conservation     

Monica Favaro  Pietro A. Vigato  Alessia Andreotti  Maria Perla Colombini 《Journal of Cultural Heritage》2005,6(4):295-305

The oil painting “La Medusa” executed by Caravaggio at the end of the XVI century on a wooden shield, was investigated by integrated physical–chemical and analytical methodologies in order to obtain scientific data capable of elucidating the state of conservation and the painting technique. Optical (OM) and electronic (SEM-EDS) microscopy, micro-FT-IR spectroscopy, gas chromatography–mass spectrometry (GC–MS) and pyrolysis GC–MS were applied on two microfragments and some organic samples obtained by solvent extraction using the swab cleaning technique. The obtained results indicated that Caravaggio probably reused an old shield as a previous gypsum preparation layer has been detected under the original painting layers. He used white lead, natural earths, verdigris and lead–tin yellow type I mixed with drying oils to paint. The considerable amount of amorphous particles of copper chlorides found in the green pigment verdigris suggests that it could have been produced according to the ancient recipe of verde salsum described by Theophilus. Mordant gilding has been identified on the upper part of the shield that can be related to an abandoned experiment to give the painting a mirror-like reflecting effect. Three different varnishes layers have been detected above the painted surface. The original and restoration varnishes have been identified and they contain a mixture of drying oil, mastic and turpentine and some beeswax. Cleaning tests, performed with different organic solvents, suggest the use of isopropyl alcohol as cleaning agent because it is less efficient in comparison to others solvents; thus it ensures a careful and controlled removal of the varnishes.  相似文献   

The impact of national research funds: A regression discontinuity approach to the Chilean FONDECYT     

José Miguel Benavente  Alessandro Maffioli 《Research Policy》2012,41(8):1461-1475

This paper analyses the role of national research funds in promoting scientific production in emerging economies. The study focuses on the impact of the Chilean National Science and Technology Research Fund (FONDECYT). The analysis uses data drawn from international sources of bibliometric information combined with the administrative records of the program's executing unit. To measure the program's impact, we implement a regression discontinuity (RD) design on principal researchers who applied for funding between 1988 and 1997 considering as outcomes both quantity (publications up to 2002) and quality (citations up to 2005) of their scientific production. Our results show significant and positive impact in terms of publications, but no impact in terms of quality of scientific production in the proximity of the program's threshold ranking.  相似文献