1,721,041 research outputs found
Social network e performance d’impresa: verso un nuovo equilibrio tra metodi per il cambiamento organizzativo, la collaborazione e la gestione dell’innovazione
No full textLa necessità di accrescere in termini di efficienza e competitività, induce
le organizzazioni a ricercare modelli di produzione e gestione basati sulla
collaborazione e sull’autonomia organizzativa, in sostituzione di quelli
tradizionali centrati sul controllo verticale end-to-end dei processi. In
strutture organizzative complesse, sempre più dinamiche ed innovative,
emergono pertanto, nuove forme di collaborazione partecipativa che tendono a cambiare il modo in cui i beni e servizi sono ideati, prodotti, distribuiti e gestiti. Sulla base di tali premesse, il presente contributo si propone di analizzare gli strumenti emergenti di collaborazione
organizzativa, con particolare riferimento allo strumento del “social
network” come veicolo di comunicazione e gestione delle informazioni in
ambito inter-intra aziendale funzionale a supportare le organizzazioni verso
una crescita condivisa ed orizzontale. Dopo aver effettuato un’analisi del contesto di riferimento e della letteratura esistente in materia, il contributo procede ad esaminare il caso
della piattaforma di un social networking aziendale, al fine di analizzare la
validità di tali strumenti di comunità virtuale per gestire le informazioni e le
conoscenze aziendali
Assessment of the effectiveness of a dehumidification system by emission of electromagnetic fields: Proposal of a protocol
No full textIn this paper the operation of a dehumidification system has been studied in operating conditions and a protocol for the assessment of its effectiveness is proposed. The physical principle of the used system is based on the interaction of a pulsed electromagnetic field with the masonry materials affected by rising damp phenomena. As it is well known, water has a crucial role in decay mechanisms both by a physical and by a chemical point of view. In fact, soluble salts transport phenomena, biological growth, stress due to expanding clays, freeze–thaw cycles, are among the most diffused examples of decay mechanisms. The target of any dehumidification systems, as the one under analysis, is very ambitious and crucial in the field of cultural heritage conservation; hence starts the authors need in understanding the involved physical mechanisms and in evaluating the effectiveness of these systems. Literature reports laboratory tests carried out with the target to acquire a better knowledge of the interaction mechanism between pulsed electromagnetic field and masonry materials, with and without water presence. Very often laboratory tests are followed by tests on pilot site chosen on purpose. In the example presented in the paper, ground floor masonries belonging to an historical building, with evident rising damp phenomena, was chosen. The building is located at Saltino, Reggello close to Florence, at 995 m asl. The rising of water affects at different levels several rooms of the building at ground floor, but on the north side of the house, the effects are greater. This contribute also proposes preliminary ideas to draw a standard aimed at build up a protocol for the performance assessment of dehumidification systems, based on different physical principles. A full knowledge of physical principles is mandatory to optimize the effectiveness of these systems. The procedure to assess the effectiveness of these systems must be standardized identifying the environmental parameters to be checked in relation to the ones directly measured on the masonry
Contribution of thermal analysis in the characterization of lime-based mortars with oxblood addition
No full textIn this study, thermogravimetry and differential scanning calorimetry (TG-DSC) along with X-ray diffraction analysis (XRD) and Fourier transform infrared (FTIR) spectroscopy in attenuated total reflectance (ATR) mode, were performed on a series of lime mortar specimens with oxblood addition. Calculated TG weight loss showed that at initial stages, oxblood addition could slow down the carbonation process. Specimens containing oxblood showed two peaks above similar to 550 degrees C in their DSC curves, and the combination of TG-DSC and ATR techniques allowed to speculate that the first peak (at lower temperatures) could correspond to the decomposition of CaCO3 at a lower degree of crystallinity (e.g. amorphous calcium carbonate (ACC), aragonite, vaterite), while the second peak (at higher temperatures) corresponded to the decomposition of calcite. Additionally, XRD and ATR results indicated that ACC was formed in the specimens containing oxblood at a first stage, and as time progresses, ACC could transform to vaterite and then to calcite
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Thin Lead Sheets in the Decorative Features in Pavia Charterhouse
No full textThe facade of the church of the Pavia Charterhouse, built at the end of the 15th century, shows outstanding decorative features made of different stone materials, such as marbles, breccias and sandstones. Magnificent ornamental elements are made of thin lead sheets, and some marble slabs are inlaid with them. Metal elements are shaped in complex geometric and phytomorphic design, to form a Greek fret in black contrasting with the white Carrara marble. Lead pins were fixed to the back of the thin lead sheets with the aim of attaching the metal elements to the marble; in so doing the pins and the lead sheets constitute a single piece of metal. In some areas, lead elements have been lost, and they have been substituted with a black plaster, matching the colour of the metal. To the authors' knowledge, this kind of decorative technique is rare, and confirms the refinement of Renaissance Lombard architecture. This work reports on the results of an extensive survey of the white, orange and yellowish layers, which are present on the external surface of the lead. The thin lead sheets have been characterized and their state of conservation has been studied with the aid of Optical Microscopy, SEM-EDS, FTIR and Raman analyses. Lead sulphate, lead carbonates and oxides have been identified as decay products
Application of Different Fourier Transform Infrared (FT-IR) Methods in the Characterization of Lime-Based Mortars with Oxblood
No full textOrganic compounds have frequently been added into lime mortars for property modifications, in order to satisfy various functional needs in building techniques. This study applies Fourier transform infrared (FT-IR) spectroscopy in transmission, reflection, and attenuated total reflection (ATR) modes to characterize lime-based mortar specimens containing oxblood, which has been used as additive as a common practice of long history in many parts of the world. The specimens were prepared basing upon a 19th-century Italian historic recipe, with the intention to have a better understanding on the possible characteristics of such mortars. Thermal analysis, color measurement, and static contact angle test were also used. After curing, the specimens show a distinctive dark-red color on the top surface, which is different from the bulk. Color measurements on the surface suggest that this color was formed at an early stage and was able to maintain stable for a relatively long period of time. Both transmission and reflection FT-IR confirm the preferential accumulation of proteins on the top surface, which should have induced their water repellency according to the static contact angle test. In addition, specimens show weaker calcite bands in FT-IR transmission, reflection, as well as ATR spectra; the pattern of ATR spectra after the thermal analysis to 500 degrees C suggests the formation of amorphous calcium carbonate, which is related to the presence of oxblood
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