1,721,045 research outputs found
Co-creating value in urban public policy contexts: a different approach
No full textUrban areas face daunting economic challenges that have increased in scope in recent years. At the same time, cities provide for opportunities for growth and value creation. The interplay of these challenges and opportunities represents an area of intervention for policymakers and researchers. However, traditional approaches to urban policy deriving from managerial and economic policy theories present difficulties mainly related to capacities to counterbalance the interests and expectations of a multitude of stakeholders participating in the value co-creation process and to allow different components to synergically contribute to the sustainability of a system. The author proposes an innovative approach to urban public policy that involves adopting the theoretical corpus of the viable systems approach (“VSA”). Urban planning is particularly analyzed as systemic components of urban areas with the aim of investigating decision-making processes that support an integrated, efficient, effective and sustainable management of territories as multidimensional, multisectoral and multi-stakeholder entities. By recovering different settings, the VSA is designed for the co-creation of value as the capacity for viable systems to increase their chances of survival in their own contexts. Value derives first from strategic decisions made to find both dyadic and context consonance. Through its strategic decisions, the governing body of the territory develops a specific system as an overall synthesis of all possible systems organized within a specific area, identifying patterns of development agreed upon by the several stakeholders of the given territory. In the dynamics of value co-creation in systemic multi-subjective organizations where levels of complexity are particularly high, research on consonance among different stakeholders is particularly important to achieve the most value for a territory. In this respect, the VSA may constitute a valid tool for finding necessary capacities to imagine evolutionary paths toward new competencies
Effects of Natural and Accelerated Artificial Aging on Durability of Cold-Curing Epoxy Resins
No full textThe knowledge about the long-term behavior of materials represents one of the primary issues to be addressed to optimize their performance in service and for economic reasons as well. In particular, the lack of data about the durability of the polymeric materials can be a limit to their wider use in structural applications, such as those involved in the rehabilitation or renewal of civil infrastructures and cultural heritage. In this case, since the materials are often used outdoors, outside exposure should represent a basic reference for the study of their durability; however, many years could be necessary to produce measurable degradation and to allow the durability assessment. Numerous procedures and devices have been designed to test weathering in shorter times, although the relationship between the natural and the accelerate aging still needs to be more detailed.
In this work the effects of natural weathering have been compared to those caused by accelerate artificial aging on the calorimetric and mechanical properties of different cold-curing epoxy resins. It was found that the variations in properties due to both natural exposure and accelerated aging are qualitatively similar. However, the selected accelerated aging procedure appeared excessively severe and not able to accurately reproduce the weathering occurred after outdoor exposure
Some cases of hydrocephalus treated by bilateral ventriculo-atrial shunt, using the Pudenz-Heyer valve system.
No full textThe artistic eclecticism of Carlo Montarsolo, between method and imagination
No full textL’autore approfondisce lo stile di un artista di levatura internazionale cogliendo le complesse problematiche che la sua produzione evoca, intrecciando un discorso riguardo al territorio, al suo carattere, alla sua tipicità, con alcuni spunti relativi alle dimensioni universali dell’agire umano
Factors Affecting the Durability in Service of Epoxy Resins Employed for Restoration of Historical Buildings
No full textThe epoxy resin, that served as either matrix and adhesive in the composite used in the restoration of the Basilica di S. Francesco, were studied. Thermal, spectroscopic and mechanical properties were evaluated on samples subjected to different thermal, hygrometric and thermo-hygrometric treatments. The comparison between the properties of the cured resin calculated before and after exposure to levels of humidity, temperature and water above the ordinary values, will provide information on durability of this products under severe conditions
Environmental effects on epoxy adhesives employed for restoration of historical buildings
No full textFiber reinforced composites based on epoxy resins are used in the restoration of historical buildings, for example in the restoration of the Basilica di S. Francesco (Assisi, Italy).
In the study presented, the epoxy resin that served as matrix in the composite, was analyzed, focusing the attention on the factors that could affect its durability in service. The characteristics
of the epoxy resin during cure were first evaluated. Thermal, chemical and mechanical properties were, then, measured on samples exposed, after curing, to levels of humidity, temperature and water above the ordinary values. The comparison between the properties of the cured resin calculated before and after the treatment, provided information on the effects of different
environmental conditions. It was found that the thermal treatments yield a post-curing process, leading to an increase in glass transition temperature and a strengthening of the system; the exposition to moisture or water gives rise to a reduction in Tg, while it does not affect considerably the mechanical properties of the resin; finally, the effects of thermohygrometric treatments are more complex
FT-IR Spectroscopy Applied to the Study of the Curing Process of Epoxy-Amine Systems: a Literature Review
No full textEpoxy resins find wide applications in many fields and have been extensively studied. In particular, great effort has been devoted to the study of the mechanism of crosslinking reactions analysing the factors affecting the molecular network and the physical properties of the hardened material. A detailed understanding of the "curing process" and of the structure-properties relationship, in fact, is essential to control and optimise the process parameters in order to tailor the performance of the of cured systems. Different analytical techniques have been employed to this aim. Among them, FTIR (Fourier transform infrared) spectroscopy has proved to be very helpful allowing quantitative measurements of the variations of functional groups during the crosslinking reactions. In the present work, a review of the scientific publications dealing with the application of FTIR to study the mechanism and the kinetic of the "curing process" of epoxy resins hardened with amines, is presented. This kind of formulation, in fact, is one of the most frequently used and, therefore, has been extensively studied. The main characteristic absorbance peaks of epoxy-amine systems have been listed and discussed. Finally, the kinetic equations more widely employed to determine the degree of conversion and the kinetic parameters, have been reported
Protein-templated copper nanoclusters for fluorimetric determination of human serum albumin
Full text linkCopper nanoclusters (CuNCs) are attractive for their unique optical properties, providing sensitive fluorescent detection of several kinds of targets even in complex matrices. Their ability in growing on suitable protein and nucleic acid templates make CuNCs efficient optical reporters to be exploited in bioanalysis. In this work, we report the specific and sensitive determination of human serum albumin (HSA) in human serum (HS) and urine via CuNCs fluorescence. HSA is the most abundant protein in plasma, and plays a key role in the early diagnosis of serious pathological conditions such as albuminuria and albuminemia. Recently, HSA has become clinically central also as a biomarker to assess severity, progression, and prognosis of various cancers. We report the controlled and reproducible growth of CuNCs directly on the target analyte, HSA, which results in a fine dose-dependent fluorescent emission at 405 nm. The protocol is optimized in water, and then applied to serum and urine specimens, without matrix pretreatment. The method linearly responds within the whole concentration of clinical interest, with a sensitivity of 1.8 ± 0.1 × 10-3 g L-1 and 0.62 ± 0.03 × 10-3 g L-1 in serum and urine, respectively, and excellent reproducibility (CVav% ca. 3% for both). The assay is designed to have a single protocol working for both matrices, with recovery of 95% (HS) and 96% (urine). The stability of the fluorescence after CuNCs formation was tested over 3 days, displaying good results (yet higher in urine than in serum)
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
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