Search results for "Mod"
showing 10 items of 39605 documents
EXTERNAL RECIRCULATION IN PRS TYPE TURBINE: EXPERIMENTAL AND NUMERICAL RESULTS.
2022
Cavitation is a relevant phenomenon for structural safety and noise level in hydraulic turbines, occurring when water pressure falls below the vapor value at a given temperature. In this case bubbles of vapor grow inside the liquid and move along with it. When the pressure returns above the vapor value the bubble collapses, and the pressure can locally achieve very high values, up to 7000 bars (Kumar & Saini, 2010). Moreover, if the bubble was confined also by the solid wall of a blade, the solid particles suspended in the fluid can be transported by the fluid ones and hit the solid wall at very high velocity, generating erosion. Cavitation is also the source of high frequency noise, ve…
PLLA scaffolds with controlled architecture as potential microenvironment for in vitro tumor model
2019
Abstract The "microenvironment" where a tumor develops plays a fundamental role in determining its progression, the onset of metastasis and, eventually, its resistance to therapies. Tumor cells can be considered more or less invasive depending both on the nature of the cells and on the site where they are located. Commonly adopted laboratory culture protocols for the investigation of tumor cells take usually place on standard two-dimensional supports. However, such cultures do not allow for reproduction of the biophysical properties of the tumor’s microenvironment, thus causing the cells to lose most of their relevant characteristics. In this work MDA-MB 231 breast cancer cells were cultiva…
Impiego di 3D Web-service e software open-source nel rilievo di reperti archeologici: valutazioni metriche
2013
The Structure From Motion (SFM) algorithms derived from Computer Vision community make image-based techniquesa competitive and user friendly approach to obtain 3D information of real objects. These algorithms have been implemented in many 3D web-service and open source softwareto develop free instruments for the reconstruction of very detailed 3D digital models. Their useare becoming very common above all in archaeological studies but their potentiality for metric application have not been tested at all.The aim of the work is to investigate the quality and the accuracy of 3D models obtained through 3D web-service and SFM open source software.Different tests have been performed using some 3D…
A Geometrical Channel Model for MIMO Mobile-to-Mobile Fading Channels in Cooperative Networks
2009
This paper deals with the modeling and analysis of narrowband multiple-input multiple-output (MIMO) mobile- to-mobile (M2M) fading channels in relay-based cooperative networks. Non-line-of-sight (NLOS) propagation conditions are assumed in the transmission links from the source mobile station to the destination mobile station via the mobile relay. A stochastic narrowband MIMO M2M reference channel model is derived from the geometrical three-ring scattering model, where it is assumed that an infinite number of local scatterers surround the source mobile station, the mobile relay, and the destination mobile station. The complex channel gains associated with the new reference channel model are…
A simulation model for wideband MIMO vehicle-to-vehicle fading channels in T-junction propagation environments
2010
In this paper, we propose a high-performance simulation model for wideband multiple-input multiple-output (MIMO) vehicle-to-vehicle (V2V) fading channels in T-junction propagation environments. The so-called Riemann sum method (RSM) is applied for the parametrisation of the simulation model. Furthermore, the statistical properties of the wideband MIMO V2V channel simulation model, such as the space-time-frequency cross-correlation function (STF-CCF), the two-dimensional spatial cross-correlation function (2D spatial CCF) and the temporal auto-correlation function (ACF) are studied. Finally, the high accuracy of the proposed simulation model is demonstrated by comparing the correlation prope…
Sensitivity of 3He NMR parameters to the proximity of heterocyclic rings. The helium–furan dimer
2014
The potential of NMR technique in probing the interaction between a noble gas atom (used as a spectroscopic probe) and five-membered heterocyclic systems was theoretically studied. Selected 3He NMR parameters of free noble gas atom and its dimer were calculated using density functional theory with three functionals (M06-2X, CAM-B3LYP, and APFD), combined with dedicated polarization-consistent basis sets, and critically compared with theoretical high level calculations from the literature. The change of sotropic nuclear magnetic shielding of free noble gas atom in the presence of furan (3He placed above he middle of the ring and used as NMR probe) increased with its proximity to the heterocy…
A FEM model of rail track-ground system to calculate the ground borne vibrations: A case of rail track with wooden sleepers and k-fastenings at Caste…
2007
The prediction of ground borne vibrations is an important issue that needs a multidisciplinary research approach. The principal topics concern both the interaction between train and rail and the interaction between rail track and ground.
Bim and architectural heritage: Towards an operational methodology for the knowledge and the management of cultural heritage
2016
The study aims to answer the growing need for virtuously organize informational apparatuses related to Cultural Heritage. We propose a methodology that integrates multidisciplinary processes of interaction with information aimed at survey, documentation, management, knowledge and enhancement of historic artifacts. It is needed to review and update the procedure of instrumental data acquisition, standardization and structuring of the acquired data in a three-dimensional semantic model as well as the subsequent representability and accessibility of the model and the related database. If the use of Building Information Modeling has in recent years seen a consolidation in the procedures and the…
CONCLUSIONS
2022
Today’s communication has almost completely entered the digital world as the only system of language, be it graphic, spoken or artistic. It is no coincidence that the architectural and cultural heritage, as well as the urban aspects of the city, could not avoid undergoing significant change caused by the influence of the digital transition which allows them to be safeguarded, documented and handed down. Digital, through all its forms, is, today, not only the representation of the asset but also its management through BIM approaches. The boundaries of representation, digitization and documentation open up and become ever wider, embracing greater goals and responding to growing needs.
Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy
2021
As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original …