91 research outputs found

    Ejector refrigeration: A comprehensive review

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    The increasing need for thermal comfort has led to a rapid increase in the use of cooling systems and, consequently, electricity demand for air-conditioning systems in buildings. Heat-driven ejector refrigeration systems appear to be a promising alternative to the traditional compressor-based refrigeration technologies for energy consumption reduction. This paper presents a comprehensive literature review on ejector refrigeration systems and working fluids. It deeply analyzes ejector technology and behavior, refrigerant properties and their influence over ejector performance and all of the ejector refrigeration technologies, with a focus on past, present and future trends. The review is structured in four parts. In the first part, ejector technology is described. In the second part, a detailed description of the refrigerant properties and their influence over ejector performance is presented. In the third part, a review focused on the main jet refrigeration cycles is proposed, and the ejector refrigeration systems are reported and categorized. Finally, an overview over all ejector technologies, the relationship among the working fluids and the ejector performance, with a focus on past, present and future trends, is presented. (C) 2015 Elsevier Ltd. All rights reserved

    A study of working fluids for heat driven ejector refrigeration using lumped parameter models

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    This paper studies the influence of working fluids over the performance of heat driven ejector refrigeration systems performance by using a lumped parameter model. The model used has been selected after a comparison of different models with a set of experimental data available in the literature. The effect of generator, evaporator and condenser temperature over the entrainment ratio and the COP has been investigated for different working fluids in the typical operating conditions of low grade energy sources. The results show a growth in performance (the entrainment ratio and the COP) with a rise in the generator and evaporator temperature and a decrease in the condenser temperature. The working fluids have a great impact on the ejector performance and each refrigerant has its own range of operating conditions. R134a is found to be suitable for low generator temperature (70-100 degrees C), whereas the hydrocarbons R600 is suitable for medium generator temperatures (100-130 degrees C) and R601 for high generator temperatures (130-180 degrees C). (C) 2015 Elsevier Ltd and IIR. All rights reserved

    A Tool to Analyze the Reading Behavior of the Users in a Mobile Digital Publishing Platform

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    Abstract. In their daily activities, users interact multiple times with mobile applications. This generates huge amounts of data related to these interactions that, when filtered and analyzed, would give insights on the behavior of the users while using an application. In this paper, we consider a real-world mobile digital publishing platform, named Viewerplus, which enables a digital, augmented fruition of content from traditional magazines. The objective is to develop a tool that allows the human editors to analyze the reading behavior of the users, by providing analytics that show how the users read magazine issues (i.e., how they browse an issue and move inside the app, which portions of an issue are most frequently read and which frequency, and which topics are of interest for the users during a reading session). The tool has been developed by employing a dataset extracted from the reading sessions of a magazine of an important international publisher. In this work we also employ the dataset to present a preliminary study of the user reading behavior

    Mitochondrial DNA Variation among Dogs of Mongolian, Tuvinian and Altaic Nomads

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    Dogs originated from the domestication of Eurasian grey wolves. From a genetic viewpoint, they can be grouped into two main clusters: the first is represented by several breeds obtained by artificial selection, whereas the second is of dogs that adapted to a human commensal lifestyle. Here we have provided a molecular survey aimed to infer on the genetic variability of dogs from nomadic camps in Mongolia, and the Republics of Tuva and Altai belonging to the Russian Federation. The results provided evidence of typical marks of expanding populations with multiple origins. Such a scenario could be the result of genetic exchanges among dogs from different camps, that were likely mediated by nomads

    Evaluation of Borderline Ovarian Tumor Recurrence Rate after Surgery with or without Fertility-Sparing Approach: Results of a Retrospective Analysis

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    Borderline ovarian tumors (BOTs) comprise 15-20% of primary ovarian neoplasms and represent an independent disease entity among epithelial ovarian cancers. The present study (Clinical Trial ID: NCT05791838) aimed to report a retrospective analysis of the management and outcomes of 86 consecutive BOTs patients, 54 of which were at a reproductive age. All patients with BOTs undergoing surgical treatment from January 2010 to December 2017 were included. Data were retrospectively reviewed. High levels of Ca-125 were observed in 25.6% of the FIGO stage I patients and 58.3% of the advanced disease patients. Fertility-sparing surgery and comprehensive surgical staging were performed in 36.7% and 49.3% of the patients, respectively. Laparotomy was the most frequent surgical approach (65.1%). The most common diagnosis at frozen sections was serous BOT (50.6%). Serous BOTs have significantly smaller tumor diameters than mucinous BOTs (p < 0.0001). The mean postoperative follow-up was 29.8 months (range 6-87 months). Three patients experienced a recurrence, with an overall recurrence rate of 3.5% (10% considering only the patients who underwent fertility-sparing treatment). BOTs have low recurrence rates, with excellent prognosis. Surgery with proper staging is the main treatment. Conservative surgery is a valid option for women with reproductive potential

    The EcoThermo project: key and innovative aspects

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    In this paper we present the most innovative aspects of the EC-FP7 EcoThermo project. The main aim of the project consists on innovating the technique of heat cost allocation in buildings with a centralized heating system, overcoming the heat cost allocator drawbacks for reliability, measurement reproducibility and traceability and contexts of applications. Given the complexity of the project, we will focus on its main aspects, such as the use of a virtual sensor to estimate the radiators heating power, the design of electronic valves fitted out with an energy harvesting system and the original wireless communication protocol

    Notulae to the Italian native vascular flora: 5.

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    In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records and confirmations to the Italian administrative regions for taxa in the genera Allium, Arabis, Campanula, Centaurea, Chaerophyllum, Crocus, Dactylis, Dianthus, Festuca, Galanthus, Helianthemum, Lysimachia, Milium, Pteris, and Quercus. Nomenclature and distribution updates, published elsewhere, and corrections are provided as supplementary material

    Activity of chemotherapy in mucinous ovarian cancer with a recurrence free interval of more than 6 months: results from the SOCRATES retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Mucinous ovarian carcinoma have a poorer prognosis compared with other histological subtypes. The aim of this study was to evaluate, retrospectively, the activity of chemotherapy in patients with platinum sensitive recurrent mucinous ovarian cancer.</p> <p>Methods</p> <p>The SOCRATES study retrospectively assessed the pattern of care of a cohort of patients with recurrent platinum-sensitive ovarian cancer observed in the years 2000–2002 in 37 Italian centres. Data were collected between April and September 2005. Patients with recurrent ovarian cancer with > 6 months of platinum free interval were considered eligible.</p> <p>Results</p> <p>Twenty patients with mucinous histotype and 388 patients with other histotypes were analyzed. At baseline, mucinous tumours differed from the others for an higher number of patients with lower tumor grading (p = 0.0056) and less advanced FIGO stage (p = 0.025). At time of recurrence, a statistically significant difference was found in performance status (worse in mucinous, p = 0.024). About 20% of patients underwent secondary cytoreduction in both groups, but a lower number of patients were optimally debulked in the mucinous group (p = 0.03). Patients with mucinous cancer received more frequently single agent platinum than platinum based-combination therapy or other non-platinum schedules as second line therapy (p = 0.026), with a response rate lower than in non-mucinous group (36.4% vs 62.6%, respectively, p = 0.04). Median time to progression and overall survival were worse for mucinous ovarian cancer. Finally, mucinous cancer received a lower number of chemotherapy lines (p = 0.0023).</p> <p>Conclusion</p> <p>This analysis shows that platinum sensitive mucinous ovarian cancer has a poor response to chemotherapy. Studies dedicated to this histological subgroup are needed.</p

    Structured reporting for fibrosing lung disease: a model shared by radiologist and pulmonologist

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    Objectives: To apply the Delphi exercise with iterative involvement of radiologists and pulmonologists with the aim of defining a structured reporting template for high-resolution computed tomography (HRCT) of patients with fibrosing lung disease (FLD). Methods: The writing committee selected the HRCT criteria\ue2\u80\u94the Delphi items\ue2\u80\u94for rating from both radiology panelists (RP) and pulmonology panelists (PP). The Delphi items were first rated by RPs as \ue2\u80\u9cessential\ue2\u80\u9d, \ue2\u80\u9coptional\ue2\u80\u9d, or \ue2\u80\u9cnot relevant\ue2\u80\u9d. The items rated \ue2\u80\u9cessential\ue2\u80\u9d by &lt; 80% of the RP were selected for the PP rating. The format of reporting was rated by both RP and PP. Results: A total of 42 RPs and 12 PPs participated to the survey. In both Delphi round 1 and 2, 10/27 (37.7%) items were rated \ue2\u80\u9cessential\ue2\u80\u9d by more than 80% of RP. The remaining 17/27 (63.3%) items were rated by the PP in round 3, with 2/17 items (11.7%) rated \ue2\u80\u9cessential\ue2\u80\u9d by the PP. PP proposed additional items for conclusion domain, which were rated by RPs in the fourth round. Poor consensus was observed for the format of reporting. Conclusions: This study provides a template for structured report of FLD that features essential items as agreed by expert thoracic radiologists and pulmonologists
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