51 research outputs found

    Gas Exchange and Injection Modeling of an Advanced Natural Gas Engine for Heavy Duty Applications

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    The scope of the work presented in this paper was to apply the latest open source CFD achievements to design a state of the art, direct-injection (DI), heavy-duty, natural gas-fueled engine. Within this context, an initial steady-state analysis of the in-cylinder flow was performed by simulating three different intake ducts geometries, each one with seven different valve lift values, chosen according to an estabilished methodology proposed by AVL. The discharge coefficient (Cd) and the Tumble Ratio (TR) were calculated in each case, and an optimal intake ports geometry configuration was assessed in terms of a compromise between the desired intensity of tumble in the chamber and the satisfaction of an adequate value of Cd. Subsequently, full-cycle, cold-flow simulations were performed for three different engine operating points, in order to evaluate the in-cylinder development of TR and turbulent kinetic energy (TKE) under transient conditions. The latest achievements in open source mesh generation and motions were applied, along with time-varying and case-fitted inizialization values for the fields of intake pressure and temperature. Finally, direct-injection of natural gas in the cylinder was incorporated in full-cycle simulations, to evaluate the effects of injection on charge motions and charge homogeneity at the estimated spark timing. Three specific engine operating points were simulated and different combinations of turbochargers and valve lift laws were tested. Results consistency was verified by means of validations with data from 1D simulations and literature

    Millimeter-wave backscattering measurements with transmitarrays for personal radar applications

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    The concept of personal radar has recently emerged as an interesting solution for next 5G applications. In fact the high portability of massive antenna arrays at millimeter-waves enables the integration of a radar system in pocket-size devices (i.e. tablets or smartphones) and enhances the possibility to map the surrounding environment by guaranteeing accurate localization together with high-speed communication capabilities. In this paper we investigate for the first time the capability of such personal radar solution using real measured data collected at millimeter-waves as input for the mapping algorithm

    Application of transmitarray antennas for indoor mapping at millimeter-waves

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    Millimeter-waves are expected to play a key role in next 5G scenario due to the availability of a large clean unlicensed bandwidth at 60 GHz and the possibility to realize packed antenna arrays, with a consequent increase of the communication capacity and the introduction of new functionalities, such as high-definition localization and personal radar for automatic environment mapping. In this paper we propose the adoption of millimeter-wave transmitarrays for personal radar applications and we investigate the impact of the radiation pattern characteristics on the map reconstruction accuracy, by analysing how the number of array elements, of quantization bits and the focal distance affect the environment reconstruction performance

    Identification of 5F-Cumyl-PINACA, a Synthetic Cannabinoid, in the Herbal Material Used for Recreational Purposes in the Province of Trieste: Public Health implications

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    In recent years, the phenomenon of the production and trade of synthetic cannabinoids has grown, becoming a public health issue worldwide. The recent accesses - to the ED of the hospital of Trieste - of people who complained episodes of hallucinations, sensation of poisoning, tachycardia, and air hunger following the inhalation of "Che Sballo platinum", have highlighted the need to perform further analysis on the contents of the packet sold as an air freshener, produced in Koper (Slovenia)

    Pancreatic transplant surgery and stem cell therapy. Finding the balance between therapeutic advances and ethical principles

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    The latest achievements in the field of pancreas transplantation and stem cell therapy require an effort by the scientific community to clarify the ethical implications of pioneering treatments, often characterized by high complexity from a surgical point of view, due to transplantation of multiple organs at the same time or at different times, and from an immunological point of view for stem cell therapy. The fundamental value in the field of organ transplants is, of course, a solidarity principle, namely that of protecting the health and life of people for whom transplantation is a condition of functional recovery, or even of survival. The nature of this value is that of a concept to which the legal discipline of transplants entrusts its own ethical dignity and for which it has ensured a constitutional recognition in different systems. The general principle of respect for human life, both of the donor and of the recipient, evokes the need not to put oneself and one's neighbor in dangerous conditions. The present ethical reflection aims to find a balance between the latest therapeutic advances and several concepts including the idea of the person, the respect due to the dead, the voluntary nature of the donation and the consent to the same, the gratuitousness of the donation, the scientific progress and the development of surgical techniques, and the policies of health promotion

    Combined Experimental and Numerical Investigation of the ECN Spray G under Different Engine-Like Conditions

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    A detailed understanding of Gasoline Direct Injection (GDI) techniques applied to spark-ignition (SI) engines is necessary as they allow for many technical advantages such as increased power output, higher fuel efficiency and better cold start performances. Within this context, the extensive validation of multi-dimensional models against experimental data is a fundamental task in order to achieve an accurate reproduction of the physical phenomena characterizing the injected fuel spray. In this work, simulations of different Engine Combustion Network (ECN) Spray G conditions were performed with the Lib-ICE code, which is based on the open source OpenFOAM technology, by using a RANS Eulerian-Lagrangian approach to model the ambient gas-fuel spray interaction. Foremost, the main scope of the activity was to identify the most accurate numerical set-up in terms of atomization ad secondary break-up models, thanks to a validation of the computed results against experimental data available for the ECN Spray G baseline condition. Specifically, attention was focused on spray penetration along with an analysis of spray morphology and effects of plume-to-plume interaction. Afterwards, the reference set-up was tested and validated under different operating conditions, characterized by detailed experimental measurements specifically provided for this work. In particular, Mie scattering and Schlieren techniques allowed the quasi-simultaneous acquisition of both vapor and liquid penetrations, while a customized image-processing procedure, developed in Matlab environment, was used for the outline of the spray contours of both fuel phases to measure the parameters characterizing the jet development. A robust reference numerical set-up was identified, capable to reproduce with good accuracy the injection process of a multi-hole GDI spray under the wide range of tested operating conditions

    MicroRNA expression profiling with a droplet digital PCR assay enables molecular diagnosis and prognosis of cancers of unknown primary

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    Metastasis is responsible for the majority of cancer‐related deaths. Particularly, challenging is the management of metastatic cancer of unknown primary site (CUP), whose tissue of origin (TOO) remains undetermined even after extensive investigations and whose therapy is rather unspecific and poorly effective. Molecular approaches to identify the most probable TOO of CUPs can overcome some of these issues. In this study, we applied a predetermined set of 89 microRNAs (miRNAs) to infer the TOO of 53 metastatic cancers of unknown or uncertain origin. The miRNA expression was assessed with droplet digital PCR in 159 samples, including primary tumors from 17 tumor classes (reference set) and metastases of known and unknown origin (test set). We combined two different statistical models for class prediction to obtain the most probable TOOs: the nearest shrunken centroids approach of Prediction Analysis of Microarrays (PAMR) and the least absolute shrinkage and selection operator (LASSO) models. The molecular test was successful for all formalin‐fixed paraffin‐embedded samples and provided a TOO identification within 1 week from the biopsy procedure. The most frequently predicted origins were gastrointestinal, pancreas, breast, lung, and bile duct. The assay was applied also to multiple metastases from the same CUP, collected from different metastatic sites: The predictions showed a strong agreement, intrinsically validating our assay. The final CUPs' TOO prediction was compared with the clinicopathological hypothesis of primary site. Moreover, a panel of 13 miRNAs proved to have prognostic value and be associated with overall survival in CUP patients. Our study demonstrated that miRNA expression profiling in CUP samples could be employed as diagnostic and prognostic test. Our molecular analysis can be performed on request, concomitantly with standard diagnostic workup and in association with genetic profiling, to offer valuable indications about the possible primary site, thereby supporting treatment decisions

    Localization method and system using non-regenerative UWB relays

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    The present invention relates to a method and a system for determining the position of an object which can be a passive or an active tag (140). The system comprises a plurality of anchor nodes (111,112) and a plurality of non-regenerative relays (121,122,123) of known positions. In case of an active tag, a UWB pulse signal is emitted by the tag and received by the anchor nodes either directly or via a relay. In case of a passive tag, UWB pulse signals are sent by the anchors nodes and reflected back, either way being either a LOS path or a relayed path. A processing node (130) collects the signals received by the anchor nodes (111,112) to estimate the position of the tag
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