177,130 research outputs found
Caratterizzazione dei materiali impiegati nella miniatura dello Speculum corsiniano mediante analisi non invasive
No full textIl saggio descrive i risultati delle analisi diagnostiche condotte sulle miniature del manoscritto 55.K.2 (Rossi 17) custodito nella "Biblioteca dell'Accademia Nazionale dei Lincei e Corsiniana" e contenente lo Speculum humanae salvationis
Synthesis of acyclic carba-nucleoside phosphonates, structural analogues to natural deoxyribonucleotides
No full textAcyclic carba-nucleoside phosphonates, modelled on natural deoxyribonucleotides have been prepared starting from DNA nucleobases and tert-butyl acrylate. The products obtained from a Michael-type reaction were elongated to beta-oxo esters that were first reduced to beta-hydroxy esters and then transformed into protected beta-hydroxy aldehydes. Wittig-Horner-Emmons reaction with the anion of tetraisopropyl methylenebisphosphonate gave, after deprotection, the desired 4-hydroxy-6-purinyl- or -6-pyrimidinyl-1-hexenylphosphonic acids. A dimer, potential precursor of acyclic polynucleotides (APN), homomorphous with DNA, was also prepared
A stand-alone micro heat pump for personalized environmental control system (PECS)
No full textThis experimental study presents the design, development, and testing of a micro-scale vapor compression (VC) heat pump prototype tailored for novel Personalized Environmental Comfort Systems (PECS). The system employs a natural refrigerant (HC-290) to align with new environmental regulations, and integrates both compressor speed and expansion valve modulation, enabling continuous and precise control of cooling power and temperature – features rarely found in miniaturized systems. A key innovation is the integration of a 20-liter heat thermal energy storage unit (either sensible or latent) to buffer condensation heat and support standalone operation up to 8 h, without outdoor ducting or heat rejection. Experimental results show that localized cooling at approximately 20 °C can be maintained even in ambient conditions up to 36 °C, with an average Energy Efficiency Ratio (EER) of around 2 when using a latent heat thermal storage system based on phase change materials. The optimized configuration delivers a stable cooling output of ∼200 W, sufficient to meet the thermal needs of a single occupant while minimizing the impact on indoor air conditions. By reducing the volume of conditioned space and enabling direct user-level control, the proposed system supports a shift toward decentralized comfort solutions, with the potential to relax central HVAC setpoints and reduce overall building energy consumption. The study also provides a comprehensive experimental characterization
A methodological framework for the analysis of the service life of VIPs based envelope components in buildings
No full textVacuum Insulation Panels (VIPs) represent one of the most promising solution for building insulation. Nevertheless the VIPs service life may be limited by water vapour as well as gas permeations. The extent of their occurrence is strictly dependent by the severity of temperature and humidity at which VIPs are exposed during their operation. In the context of IEA EBC Annex 65 activities, a common simulation based procedure was introduced to identify potential critical hygrothermal working conditions for VIPs when they are used in different building components. A methodological framework was developed to estimate the yearly profiles of temperature and relative humidity at the boundaries of VIPs considering different indoor and external conditions and envelope configurations.
This procedure provided general data suggesting guidelines for the correct design
of VIP based building components considering their actual working conditions
Sulle tracce di una metodologia sociale appresa collettivamente
No full textOrmai, sia per ragioni di competenze collettive, sia per la facilitazione comunicativa dovuta all'Web 2.0, molte procedure metodologiche sono apprese contemporaneamente in forma collettiva
Low-Cost Tracer Gas Sensor for Building Ventilation
No full textThe accurate assessment of Indoor Air Quality is crucial for occupant health, yet traditional methods for evaluating ventilation rates, such as tracer gas techniques using photoacoustic spectroscopy (PAS), face limitations in cost, logistics, and response time. This study presents the development and validation of a low-cost, fast-response sensor system for tracer gas measurement, capable of detecting multiple gases. The sensor employs a Non-Dispersive Infrared (NDIR) detector with wireless communication based on the asynchronous Bleak protocol, enabling spatially resolved IAQ monitoring. Laboratory validation using SF6 as tracer gas in a small volume of 40 liters and against the PAS reference device demonstrated an accuracy within ±20% for ventilation rates between 1 and 7 air changes per hour (ACH). Unlike PAS, which provides one measurement per minute, the low-cost sensor captures up to 50 readings per second, offering superior tracking of transient ventilation events and dynamic IAQ variations. The results suggest that this system provides a practical alternative for real-time IAQ monitoring, supporting energy-efficient and health-conscious building management
Bladder endometriosis: laparoscopic treatment and follow-up.
No full textObjectives: This study aims to show the treatment outcome in women affected by isolated bladder endometriosis who underwent laparoscopic surgery in our units. Only women with deep nodules located in the bladder were selected, thus excluding women with deep lesions located in other sites. Study design: Between March 2005 and 2007, women with deep vesical endometriosis, referring to the Departments of Obstetrics and Gynaecology of University Hospitals "G. Martino" of Messina, "Paolo Giaccone" of Palermo and "San Paolo" of Milano, were respectively recruited. A preoperative assessment of the pathology was performed. Women who were concomitantly diagnosed deep nodules of the rectovaginal septum and/or endometriotic ovarian cysts were excluded. A medical therapy with oral contraceptive and/or GnRH analogues was first proposed to the patients affected. If medical treatment failed, a laparoscopic treatment was suggested. We performed a segmental resection of the involved wall or an extramucosal dissection of the bladder according to the cases. A clinical and an instrumental evaluation by ultrasound was performed every 6 months after surgery for the first year and subsequently every 12 months. At the time of referral, patients were also questioned about any recurrence of symptoms. Results: Eight women, with a mean age of 33.8 (range 30-37 years; S.D. = 2.5) and a mean parity of 1 (range 0-2) were recruited. Medical therapy failed in all cases and the women underwent laparoscopic treatment. Surgery was complete in all cases without a need for ureteral cannulation. No intraoperative complications occurred. The mean estimated blood loss was 98 ml (range 40-200 ml). All patients underwent at least the first follow-up assessment. In none of the women, recurrence of bladder endometriotic nodules was documented. In contrast, urinary symptoms were reported in three cases. Nevertheless, all the patients reported improvement of symptoms and declared to be satisfied. Conclusions: We recommend surgical eradication of bladder lesions. Laparoscopic treatment, in the hands of an expert surgeon, is the management of choice. It offers the best approach to the diagnosis allowing good long-term results, with a less invasive approach. Large multicentric studies are however required prior to drawing definite conclusions. © 2008 Elsevier Ireland Ltd. All rights reserved
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