Search results for "Forming."
showing 10 items of 1704 documents
Didactics of ICT in Secondary Education: Conceptual Issues and Practical Perspectives
2009
Article published in the journal: Issues in Informing Science and Information Technology. Also available from the publisher: http://iisit.org/Vol6/IISITv6p153-178Hadjerrouit605.pdf While there is a huge research literature on the field of ICT (Information and Communication Technology) as a tool in teaching and learning, there is much less research on the area of ICT as a subject or similar designations such as school informatics. As a result, there is a lack of theoretical grounding of the didactics of ICT and associated teaching and learning processes. One of the main reasons for the lack of theoretical underpinnings of the didactics of ICT is that there have been in the past and there per…
Gelation of smectic liquid crystal phases with photosensitive gel forming agents.
2020
This paper studies the potential of 3 newly synthesized low molecular weight gelling agents (2 of them with azo groups) with the semicarbazide group as a H-bonding motif to gel the smectic phase of a commercial chiral smectic C material. To detect gelation two methods were used: the stabilization of the director pattern, which measures the interaction of the physical gel network with the LC-director, and the suppression of the onset of electrohydrodynamic instabilities, which measures the increase of viscosity. Special emphasis was put on the influence of the photochemical - isomerization of the gelling agents on gelation.From the stabilization of the director pattern an elastic component c…
Análise semiótico e discursivo dos filmes: "Deus e o diabo na terra do Sol" e "O dragão da maldade contra Santo Guerreiro", de Glauber Rocha
2016
ABSTRACT In 1964, Glauber Rocha directed the film Black God, White Devil year when Brazil suffered a military coup state. Due to strong censorship at the time, the dialogue about political or social issues was forbidden. Despite all that chaos, Glauber Rocha wrote and directed Black God, White Devil and Antonio das Mortes that deal with the dichotomy between good / evil, educated / uneducated, order / disorder, the social, the symbolic constructions of space as semiosphere, borders and their breaks causing chaos. For the director, religion is closely related to politics. The desire for power is enshrined in relations: political and social (interest of the owners on the workers) and religiou…
Design of the Tube Roll Forming Process Through an Heuristic Algorithm
2002
In the paper the design of an industrial tube roll forming process is developed utilizing an heuristic algorithm, namely the simulated annealing (SA). In particular both the number and the shape of the deforming rolls are determined in order to define the forming sequence. The effectiveness of the results supplied by the SA algorithm is verified both by means of some experiments tests carried out on an industrial tube roll forming equipment and through a set of numerical simulations of the process.
Knowledge-Based Systems and F.E. Simulations in Metal-Forming Processes Design An integrated Approach
1991
Summary The automatic computer aided planning and design of cold forming processes includes several phases, among which the most important are the optimal choice of the forming operations sequence and, for each operation, the determination of the more suitable operating parameters. With this aim the Authors propose an integrated approach based on the preliminary choice of some feasible forming sequences, carried out by means of a knowledge-based system, and on the subsequent determination of the optimal one employing a finite element simulation of the process.
Rubber Forming Processes of Thin Sheets
1999
In the last decade flexible media have been increasingly utilized in sheet metal drawing processes in order to reduce the tooling cost and to improve the product quality. In the present paper an axisymmetric deep drawing process of thin steel sheets is taken into account: in particular a flexible pad is utilized in order to simplify the tooling set. The process mechanics is investigated through numerical simulations and experimental tests with the aim to find out a proper set of operative parameters allowing the stamping of sound components and to highlight the particular deformation path of the drawing cup. The comparison between the numerical predictions and the experimental verification …
Macroalgal forest vs sea urchin barren: Patterns of macro-zoobenthic diversity in a large-scale Mediterranean study: Macro-zoobenthos of barren and m…
2020
The study aimed at contributing to the knowledge of alternative stable states by evaluating the differences of mobile and sessile macro-zoobenthic assemblages between sea urchin barrens and macroalgal forests in coastal Mediterranean systems considering a large spatial scale. Six sites (100 s km apart) were selected: Croatia, Montenegro, Sicily (Italy), Sardinia (Italy), Tuscany (Italy), and Balearic Islands (Spain). A total of 531 taxa, 404 mobile and 127 sessile macro-invertebrates were recorded. Overall, 496 and 201 taxa were found in macroalgal forests and in barrens, respectively. The results of this large-scale descriptive study have met the expectation of lower macrofauna complexity …
Signals of loss: Local collapse of neglected vermetid reefs in the western Mediterranean Sea
2022
During the summer of 2022, an extensive die-off of Dendropoma cristatum and other marine organisms associated with vermetid reefs was observed in the western Mediterranean Sea (northern coast of Sicily). Quantitative data from more than 300 km of coastal stripe indicated that the percentage of dead D. cristatum specimens, showing empty and/or transversely fractured shells, ranged from 64 to 84 % in populations having a density of 2900-4730 ind./m2, suggesting that millions of organisms had recently died along the Sicilian coast. This high mortality range coincided with prolonged desiccation events during which biogenic vermetid reefs were exposed to extreme warm-air conditions for several c…
Wharton’s Jelly Mesenchymal Stromal Cells Support the Expansion of Cord Blood–derived CD34+Cells Mimicking a Hematopoietic Niche in a Direct Cell–cel…
2018
Wharton’s jelly mesenchymal stromal cells (WJ-MSCs) have been recently exploited as a feeder layer in coculture systems to expand umbilical cord blood–hematopoietic stem/progenitor cells (UCB-HSPCs). Here, we investigated the role of WJ-MSCs in supporting ex vivo UCB-HSPC expansion either when cultured in direct contact (DC) with WJ-MSCs or separated by a transwell system or in the presence of WJ-MSC–conditioned medium. We found, in short-term culture, a greater degree of expansion of UCB-CD34+cells in a DC system (15.7 ± 4.1-fold increase) with respect to the other conditions. Moreover, in DC, we evidenced two different CD34+cell populations (one floating and one adherent to WJ-MSCs) with …
Theoretical Investigation of Aqueous Phase Reforming of 1,2 Propanediol over a Pt catalyst
2015
Aqueous Phase Reforming (APR) process is one of the most efficient solution for producing hydrogen from biomass renewable feedstocks, such as polyalcohols. [1] Generally the reaction is catalyzed by supported platinoid metals and among these platinum has been recognized as the most active and selective toward the production of hydrogen. However, due to its really high complexity, the reaction mechanism is today poorly understood. DFT methods can be useful for understanding the APR catalytic mechanism at atomistic level. A detailed mechanistic study was carried out using a Pt30 cluster for the modelization of the catalyst and 1,2 propanediol (1,2PDO) as a model feedstock for the APR. Even fo…