Search results for "CRAC"
showing 10 items of 1418 documents
ChemInform Abstract: Catalytic Activity of Large-Pore High Si/Al Zeolites: Cracking of Heptane on H-Beta and Dealuminated HY Zeolites
1988
Abstract The catalytic activity, selectivity, catalyst decay, thermal and hydrothermal stability, and acidity of H-Beta and HY zeolites with Si Al ratios of 7.5 and 10, respectively, have been studied during cracking of n-heptane at 450 °C and atmospheric pressure. It has been found that the H-Beta zeolite is more active and decays more slowly than HY. H-Beta presents a higher steric hindrance for dibranched molecules and therefore its open structure should be smaller than that of HY. A lower hydrogen transfer activity and hydrothermal stability is observed for H-Beta in comparison with the corresponding HY.
Thermodynamics and continuum fracture mechanics for nonlocal-elastic plastic materials
2002
Nonlocal elasticity is used as an improved elasticity model which engenders no crack-tip stress singularities and thus makes applicable the classical stress-based failure criteria. Considering nonlocal-elastic plastic materials exposed to softening by particle decohesion in a process surface and to subsequent surface separation by fracture, fracture mechanics is addressed within the framework of irreversible internal-variable thermodynamics in the hypothesis of small strains and arbitrary (but sufficiently regular) fracture surface (crack surface plus process surface). The state equations and the energy dissipation densities are derived for the bulk material and for the process surface, for…
Crack growth analysis at adhesive–adherent interface in bonded joints under mixed mode I/II
2008
The propagation of an interface crack subjected to mixed mode I/II was investigated for two 2024-T351 aluminum thin layers joined by means of DP760 epoxy adhesive produced by 3M©. On the basis of beam theory, an analytical expression for computing the energy release rate is presented for the mixed-mode end loaded split (MMELS) test. The analytical strain energy release rate was compared by finite element (FE) analysis using the virtual crack closure technique (VCCT). Several fatigue crack growth tests were carried out in a plane bending machine to compare the experimental energy release rates to those of the analytical and FE solutions. Experimental results showed the relationship between t…
Influence of Heat Treatment on Fatigue Crack Growth in Ti-6Al-4V Alloy
2011
The paper contains the results of experimental work carried out in order to analyse the initiation and propagation of fatigue cracks in Ti-6Al-4V titanium alloy. The tests were performed on plane specimens with the stress concentrators in form of one-sided sharp notches. The tested specimens were made of the oxygenated Ti-6Al-4V subjected to various variants of heat treatment.
FEM analysis of push-out test response of Hybrid Steel Trussed Concrete Beams (HSTCBs)
2015
Abstract Aiming to investigate the steel truss–concrete stress transfer mechanism in Hybrid Steel Trussed–Concrete Beams (HSTCBs), a three-dimensional (3D) nonlinear Finite Element (FE) model is developed. The constitutive relationship of the steel composing the plates and the rebars is modeled by means of a quadri-linear law, while the concrete behavior is defined by means of a Concrete Damaged Plasticity (CDP) model, suitable for modeling concrete and brittle materials. Two main failure mechanisms are considered, namely the tensile cracking and the compressive crushing. In order to accurately grasp the complicate dowel and bond phenomena arising at the steel–concrete interface, a 3D solid…
The shape of eParticipation:Characterizing an emerging research area
2008
Author's version of an article published in Government Information Quarterly, 25 (2008), 400-428. Also available from the publisher at: http://dx.doi.org/10.1016/j.giq.2007.04.007 The phenomenon of eParticipation is receiving increasing attention, demonstrated by recent technology implementations, experiments, government reports, and research programs. Understanding such an emerging field is a complex endeavor because there is no generally agreed upon definition of the field, no clear overview of the research disciplines or methods it draws upon, and because the boundaries of the field are undecided. Using conventional literature review techniques, we identify 131 scientific articles consid…
Overload of Medical Documentation: A Disincentive for Healthcare Professionals
2020
This review addresses the theories concerning the development and functioning of medical bureaucracy creating an excess of the patient records. An ever-growing number of medical files comply with the typical development of the bureaucratic management of an entrepreneurial organization, an essential feature of which is the life cycle of documentation. When the life cycle ends, an update is created with a multiplication of forms and items to be filled out, resembling that of what happens with the outdated computer program. Yet medical records should have a logical and well-functioning structure using the language of computer science in the form of a cascade or evolutionary model. Further, we …
Popolo e opinione pubblica nel pensiero di Luigi Sturzo
2021
Luigi Sturzo si occupa di opinione pubblica in relazione al sistema di governo. Secondo Sturzo, «in via generale il popolo, come opinione pubblica, riesce ad essere una forza di controllo e di limitazione dello Stato o meglio degli organi statali che si presume eseguano la sua volontà. Ciò avviene per una fondamentale esigenza della società politica, quella della limitazione dei poteri». Ma non è solo questo. In quell’equilibrio di libertà e autorità di cui spesso parla Sturzo, è necessario che i cittadini abbiano un ruolo; che tutti possano godere della libertà e partecipare al governo non in quanto individui isolati, ma come popolo organizzato e consapevole. Luigi Sturzo deals with public…
Dynamics in the Field of Museums: Contemporary Challenges for Polish Museologists
2018
The aim of this text is to present and analyze the attitudes of Polish museologists towards the changes currently taking place in the field of museums. More specifically, it will focus on their opinions regarding the evolution of museums—from the traditional model, based on symbolic violence, to the contemporary model, which accents the subjectivity of the audience. Its conclusions, based on analyses of 26 qualitative interviews with employees of Polish museums, are as follows: the organizational changes taking place in Polish museums do not relieve museologists from bureaucratic work; the collections in museums distinguish them from other institutions of culture; there is a struggle …
Municipal Building Regulations for Energy Efficiency in Southern Italy
2014
The building sector is still one of the most energy consuming sectors in Italy, like developed countries in Europe. At European level, the main policy driver related to the energy use in buildings is the Energy Performance of Buildings Directive (EPBD, 2002/91/EC) and its recast. Through the EPBD in- troduction, requirements for certification, inspections, training or renovation are now imposed in Member States. In order to fulfill the expected changes, local regulations are a key factor aiming at sustainable territorial planning. It is thus required support the issue of local rules at municipal level in order to guide local administrators and technicians and to limit discretional power of …