Search

The decarbonization of the shipping industry is pushing towards the introduction of low-carbon fuels such as hydrogen carriers and towards the installation of cleaner propulsion systems. Among different hydrogen carriers, ammonia (NH3) is considered a promising option due to its high volumetric energy density and to its easier storage and transportation in comparison with pure hydrogen. Therefore, this study is focused on the design, modeling, and feasibility assessment of ammonia-based propulsion systems for shipping applications. Two NH3-based fuel cell power generation systems are analyzed: i) a NH3-based Proton exchange membrane Fuel Cell (PEMFC) system and ii) a NH3-based Solid Oxide Fuel Cell (SOFC) system. These systems are designed to replace a conventional diesel powertrain installed on board a container ship. The fuel consumption, according to the ship load profile, is calculated and the analysis on the masses and volumes of the fuel storage tanks and of the ammonia powertrain systems is performed. Results highlight that on board installation of the proposed ammonia-based propulsion technologies causes greater masses and volumes with respect to the conventional diesel system. This criticality, in the face of an advantage in terms of avoided CO2 emissions per cruise, could be overcome by accepting a cargo capacity reduction. It is estimated a cargo reduction in the range 3.3% − 4.8% for the proposed fuel cell-based powertrain solutions. However, by valorizing the avoided CO2 emissions, it is possible to recover the economic penalty due the cargo reduction and break-even with the reference diesel scenario.

In this work, experimental results on the behavior of single chamber air-cathode microbial fuel cells, fed by composite food waste, are illustrated. Specific interest has been focused on the presence/absence of a Nafion membrane, the influence of horizontal/vertical cell layout and on the amount of water inside the cells, in order to evaluate the performances in different configurations. A remarkable increment of performances is observed when a Nafion membrane is used or when the composite food waste has a low Solid-to-Liquid ratio. Resultsshowed that values of about 380-550 mV, for the open circuit voltage, and power density of 16-27 mW/m2 areachieved when Nafion/Vertical or Nafion/Conditioned/Horizontal configurations are used. The most limiting factors to power generation can be attributed to the high water losses, when Nafion is absent, and to the high internal resistance, when a thick cathode is used instead of a thin carbon cloth.

The aim of the SYRMA-CT collaboration is to set-up the first clinical trial of phase-contrast breast CT with synchrotron radiation (SR). In order to combine high image quality and low delivered dose a number of innovative elements are merged: a CdTe single photon counting detector, state-of-the-art CT reconstruction and phase retrieval algorithms. To facilitate an accurate exam optimization, a Monte Carlo model was developed for dose calculation using GEANT4. In this study, high isotropic spatial resolution (120 μm)3 CT scans of objects with dimensions and attenuation similar to a human breast were acquired, delivering mean glandular doses in the range of those delivered in clinical breast CT (5–25 mGy). Due to the spatial coherence of the SR beam and the long distance between sample and detector, the images contain, not only absorption, but also phase information from the samples. The application of a phase-retrieval procedure increases the contrast-to-noise ratio of the tomographic images, while the contrast remains almost constant. After applying the simultaneous algebraic reconstruction technique to low-dose phase-retrieved data sets (about 5 mGy) with a reduced number of projections, the spatial resolution was found to be equal to filtered back projection utilizing a four fold higher dose, while the contrast-to-noise ratio was reduced by 30%. These first results indicate the feasibility of clinical breast CT with SR. [ABSTRACT FROM AUTHOR]

Purpose: The primary endpoint of the study was to quantitatively evaluate the presence of IIB neck level metastases in patients with laryngeal carcinoma, to provide valuable evidence to aid surgeons in the decision-making process for neck dissections. As a secondary aim this study analyzed the presence of factors that may be associated with a higher prevalence of metastasis., Methods: Two independent authors (EE, MVV) searched for articles on PubMed, Cochrane, Embase, and Scopus databases. Review of the articles was carried out following 2020 PRISMA guidelines, all articles were assessed for quality according to NICE guidelines. Afterwards the statistical analysis was performed with STATA 18SE software. Studies were also assessed for heterogeneity and risk of publication bias., Results: A total of 19 studies were included, from which data on 1205 subjects was extracted. Out of 997 patients with a cN0 LC, 21 patients developed metastasis. This meta-analysis found the cumulative rate of metastasis to be 1% (95% CI 0-2%). Also, there is a 51% higher probability (OR: 1.51, 95% CI 0.06, 2.92) of occult IIB metastasis in higher stages (T3/T4) compared to lower stages (T1/T2)., Conclusions: Dissection of level IIB may be safely spared in patients with cN0 laryngeal cancer, possibly leading to improved QoL and shoulder function as well as reducing OR times and costs., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The aim of this multicenter study was to evaluate the effectiveness and safety of electrochemotherapy (ECT) for the treatment of mucosal tumors in the head and neck. A total of 71 patients with 84 nodules of different histologies in the oral cavity, pharynx and larynx treated by ECT were evaluated. The data were collected from the InspECT database from 10 participating centers throughout Europe. Primary and recurrent/secondary tumors of different histologies were treated. The overall response rate was 65 %, with a 33 % complete response rate with limited side effects. The response rates of the primary and secondary tumors were not different. However, smaller tumors responded better than tumors larger than 3 cm in diameter. Furthermore, the tumors that were treated with curative intent responded significantly better than those treated with palliative intent. This study demonstrated the feasibility, safety and effectiveness of ECT in a larger cohort of patients with mucosal lesions in the head and neck region. Based on the available data, ECT can be used for the treatment of recurrent and, in some cases, primary mucosal tumors located in the oral cavity, larynx, and pharynx. A better response was obtained in patients with smaller primary tumors treated with curative intent., Competing Interests: Declaration of competing interest Francesca de Terlizzi is an IGEA employer. No other authors have conflicts of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: High-resolution, photon-counting, energy-resolved detector with fast-framing capability can facilitate simultaneous acquisition of precontrast and postcontrast images for subtraction angiography without pixel registration artifacts and can facilitate high-resolution real-time imaging during image-guided interventions. Hence, this study was conducted to determine the spatial resolution characteristics of a hexagonal pixel array photon-counting cadmium telluride (CdTe) detector., Methods: A 650 μm thick CdTe Schottky photon-counting detector capable of concurrently acquiring up to two energy-windowed images was operated in a single energy-window mode to include photons of 10 keV or higher. The detector had hexagonal pixels with apothem of 30 μm resulting in pixel pitch of 60 and 51.96 μm along the two orthogonal directions. The detector was characterized at IEC-RQA5 spectral conditions. Linear response of the detector was determined over the air kerma rate relevant to image-guided interventional procedures ranging from 1.3 nGy/frame to 91.4 μGy/frame. Presampled modulation transfer was determined using a tungsten edge test device. The edge-spread function and the finely sampled line spread function accounted for hexagonal sampling, from which the presampled modulation transfer function (MTF) was determined. Since detectors with hexagonal pixels require resampling to square pixels for distortion-free display, the optimal square pixel size was determined by minimizing the root-mean-squared-error of the aperture functions for the square and hexagonal pixels up to the Nyquist limit., Results: At Nyquist frequencies of 8.33 and 9.62 cycles/mm along the apothem and orthogonal to the apothem directions, the modulation factors were 0.397 and 0.228, respectively. For the corresponding axis, the limiting resolution defined as 10% MTF occurred at 13.3 and 12 cycles/mm, respectively. Evaluation of the aperture functions yielded an optimal square pixel size of 54 μm. After resampling to 54 μm square pixels using trilinear interpolation, the presampled MTF at Nyquist frequency of 9.26 cycles/mm was 0.29 and 0.24 along the orthogonal directions and the limiting resolution (10% MTF) occurred at approximately 12 cycles/mm. Visual analysis of a bar pattern image showed the ability to resolve close to 12 line-pairs/mm and qualitative evaluation of a neurovascular nitinol-stent showed the ability to visualize its struts at clinically relevant conditions., Conclusions: Hexagonal pixel array photon-counting CdTe detector provides high spatial resolution in single-photon counting mode. After resampling to optimal square pixel size for distortion-free display, the spatial resolution is preserved. The dual-energy capabilities of the detector could allow for artifact-free subtraction angiography and basis material decomposition. The proposed high-resolution photon-counting detector with energy-resolving capability can be of importance for several image-guided interventional procedures as well as for pediatric applications.

Solvent-free microwave extraction (SFME) has been proposed as a green method for the extraction of essential oil from aromatic herbs that are extensively used in the food industry. This technique is a combination of microwave heating and dry distillation performed at atmospheric pressure without any added solvent or water. The isolation and concentration of volatile compounds is performed in a single stage. In this work, SFME and a conventional technique, hydro-distillation HD (Clevenger apparatus), are used for the extraction of essential oil from rosemary (Rosmarinus officinalis L.) and are compared. This preliminary laboratory study shows that essential oils extracted by SFME in 30min were quantitatively (yield and kinetics profile) and qualitatively (aromatic profile) similar to those obtained using conventional hydro-distillation in 2h. Experiments performed in a 75L pilot microwave reactor prove the feasibility of SFME up scaling and potential industrial applications., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC) from non-Volatile Organic Compounds (NVOC) of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant.

Gamma-ray bursts (GRBs) are highly energetic explosions signaling the death of massive stars in distant galaxies. The Gamma-ray Burst Monitor and Large Area Telescope onboard the Fermi Observatory together record GRBs over a broad energy range spanning about 7 decades of gammaray energy. In September 2008, Fermi observed the exceptionally luminous GRB 080916C, with the largest apparent energy release yet measured. The high-energy gamma rays are observed to start later and persist longer than the lower energy photons. A simple spectral form fits the entire GRB spectrum, providing strong constraints on emission models. The known distance of the burst enables placing lower limits on the bulk Lorentz factor of the outflow and on the quantum gravity mass.