587 research outputs found
Dual-PEEC Modeling of a Two-Port TEM Cell for VHF Applications
No full textTwo-port TEM cells with rectangular cross section are commonly used to produce plane electromagnetic waves with high electric field. The non-uniform structure makes the use of numerical methods extremely useful in the design phase in order to achieve a very good behavior of the TEM cell over a wide frequency range of operation. In this paper an extended version of PEEC is used to study a real device and results are compared with experimental ones
DIRECT GEOREFERENCING APPROACHES FOR CLOSE-RANGE AND UAV PHOTOGRAMMETRY IN THE BUILT HERITAGE DOMAIN
No full textDirect georeferencing uses onboard sensors to measure the position and orientation of the camera during image acquisition for photogrammetric applications. This approach aims to eliminate the use of traditional Ground Control Points (GCPs) in the photogrammetric process in order to reduce the costs and the time of the survey operations. The direct georeferencing technique involves integrating measurements from inertial measurement units (IMUs) and Global Navigation Satellite Systems (GNSS) data in order to evaluate the position and attitude of the camera with high accuracy (a few centimeters). In the Built Heritage survey domain, this approach is mainly followed by the employment of UAVs (Uncrewed aerial systems) platforms that are nowadays equipped with highly accurate systems able to evaluate the external parameters for the photogrammetric process. For terrestrial applications, few already achieved tests were performed; moreover, the sensors today available for extracting information from close-range acquisition systems are limited and sometimes under development. To evaluate the possibility offered by these new direct georeferencing tools, a test on the 3D ImageVector (REDcatch GmbH) has been performed. The results and the strategies followed will be presented and analyzed in order to understand better the accuracy and the potentiality of this new promising approach
Kinetics of the free radical grafting of diethyl maleate onto linear polyethylene
No full textA study of the kinetics of diethyl maleate (DEM) grafting onto linear polyethylene (HDPE) initiated by dicumyl peroxide (DCP), was performed by differential scanning calorimetry (DSC) which allows the determination of kinetic parameters such as the activation energy Ea and the order of the reaction n. The calculated kinetic parameters depend on the conditions and vary with the feed composition: in particular the values of Ea and n increase with increasing of DCP/DEM ratio because of secondary reactions such as chain extension and degradation. A mathematical model based on the kinetic equations is proposed; it can be used to select feed composition and process parameters to obtain the desired products
NONINVASIVE DETECTION OF ENDOTHELIAL DYSFUCTION BY COLOR DOPPLER ULTRASOUND (CDU) IN KIDNEY-PANCREAS (Kp) AND KIDNEY-ALONE (KA) TRANSPLANTED PATIENTS
No full textNONINVASIVE DETECTION OF ENDOTHELIAL DYSFUNCTION BY COLOR DOPPLER ULTRASOUND (CDU) IN KIDNEY-PANCREAS (KP), KIDNEY-ALONE (KA) AND ISLET-CELLS (IC) DIABETIC TRANSPLANTED PATIENTS
No full textAprioristic Integration of Process Operations and Risk Analysis: Definition of the Weighted F&EI-Based Concept and Application to AG2S Technology
No full textThe definition of process operations and risk analysis
is two mandatory
steps in the basic/detailed engineering phases of chemical plants.
Both steps are usually performed with interdisciplinary tasks but
in segregated ways and within converging iterative procedures where
the output of the one is feeding the other step and vice versa. This
work aims to propose a different, integrated approach to implement
process and risk analysis aprioristically at the conceptualization
stage of a process and to compare quantitatively emerging technologies
in terms of intrinsic safety. In doing so, an extension of the Fire
& Explosion Index (F&EI) is formulated in order to link it
to the operational conditions of the plant directly. It is implemented
for the first time in AspenHysys to dynamically assess the impact
of optimal operating process conditions on the F&EI. Acid Gas
dynamically to Syngas (AG2S) technology for converting H2S and CO2 into syngas is selected as a case study
Modeling of polymerization reactions. I. The cationic polymerization of isobutylene by aluminum organic compounds
No full textA mathematical model is developed for the polymerization of isobutylene initiated with Et//2AlCl plus Cl//2. Previous experiments have shown that this polymerization is 'kinetically living'. A computer analysis based on a mathematical model permits the calculation of the theoretical conversion-time curves, the molecular weight averages, and polydispersity. The good agreement between experimental and theoretical results suggests that the reaction mechanism proposed and the mathematical model derived are quite correct
Fotogrammetria da UAV (Unmanned Aerial Vehicle): un'opportunità per il rilievo 3D multiscala
No full textNell’estate 2011, le attività di rilievo metrico 3D per la documentazione dello scavo archeologico di via Gemina in Aquileia, concordate in collaborazione tra il gruppo di ricerca di Geomatica del Politecnico di Torino e il Dipartimento di Scienze dell’Antichità (ora DiSU) dell’Università degli Studi Trieste, ebbero una svolta nella direzione dell’applicazione di tecnologie innovative. Oltre l’introduzione di tecniche di scanning laser terrestri descritte nel capitolo precedente e integrate a quelle della fotogrammetria terrestre fino ad allora sperimentate, si aggiunse la fotogrammetria da mezzi aerei non convenzionali, che da quegli anni ha avuto un enorme sviluppo nelle applicazioni del rilevamento, anche e in misura consistente in ambito archeologico.
In seguito all’acquisizione del know-how inerente questa nuova tecnologia da parte del gruppo di Geomatica, e dopo essersi dotati della strumentazione e aver messo a punto il metodo studiando il funzionamento e i piani di volo sia in laboratorio che nei campi volo, l’esperienza di Aquileia nel 2011, applicata al tratto di cardine e alla domus allora in luce, rappresenta la prima esperienza applicativa reale, che ha avuto un esito
estremamente positivo e che quindi ricordiamo a distanza di qualche anno con estremo interesse. Questo capitolo sarà quindi dedicato a ripercorrere l’esperienza e a presentare i risultati, che saranno accompagnati alla fine da alcune brevi considerazioni sull’evoluzione ulteriore oggi disponibile, cioè la ripresa di immagini oblique oltreché nadirali, che contribuiscono a rendere il metodo sempre più efficace per le applicazioni nel campo del patrimonio culturale
UP4DREAM CAPACITY BUILDING PROJECT: UAS BASED MAPPING IN DEVELOPING COUNTRIES
No full textUP4DREAM (UAV Photogrammetry for Developing Resilience and Educational Activities in Malawi) is a cooperative project cofounded by ISPRS between the Polytechnic University of Turin and the United Nations Children Fund (UNICEF) Malawi, with the support of two local Universities (Lilongwe University of Agriculture and Natural Resources, and Mzuzu University), and Agisoft LLC (for the use of their photogrammetry and computer vision software suite). Malawi is a flood-prone landlocked country constantly facing natural and health challenges, which prevent the country's sustainable socio-economic development. Frequent naturals shocks leave vulnerable communities food insecure. Moreover, Malawi suffers from high rates of HIV, as well as it has endemic malaria. The UP4DREAM project focuses on one of the drone project's critical priorities in Malawi (Imagery). It aims to start a capacity-building initiative in line with other mapping missions in developing countries, focusing on the realization and management of large-scale cartography (using GIS - Geographic Information Systems) and on the generation of 3D products based on the UAV-acquired data. The principal aim of UP4DREAM is to ensure that local institutions, universities, researchers, service companies, and manufacturers operating in the humanitarian drone corridor, established by UNICEF in 2017, will have the proper knowledge and understanding of the photogrammetry and spatial information best practices, to perform large-scale aerial data acquisition, processing, share and manage in the most efficient, cost-effective and scientifically rigorous way
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