228 research outputs found

    Design of a New System of High-power Efficiency Conditioning Cogeneration Energy for a Building of the University of Cagliari with Fossil Fuel Plants

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    Abstract An analysis of Italy's National Energy Budget of in the last decades shows the important role of the civil sector and the impact of fossil fuels in air conditioning systems. The high consumption of fossil fuel is Likely due to the predominance of plants with conventional boilers in buildings. Based on the analysis of the Exergy flow this paper proposes the Cogeneration technology for Air conditioning systems with heat pumps to implement the Rational Use of Energy. The feasibility of a retrofit intervention on existing systems of a large size is shown, by the projection of a cogeneration plant for the buildings of the University of Cagliari currently equipped with fossil fuel plants

    Solar Energy System in A Small Town Constituted of A Network of Photovoltaic Collectors to Produce Electricity for Homes and Hydrogen for Transport Services of Municipality

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    The supply of Energy resources to the villages located in inland and hilly regions, is disadvantageous both for the domestic and transport purposes. Because these conditions may produce the depopulation of the inland zone, a smart way to ease this inconvenience is to produce in situ electrical Energy for houses and fuel for cars, getting them from an available Energy source in the village, as the solar Energy. The only technology to produce hydrogen ecologically and to minimize CO2 emission, is through RES (Renewable Energy Sources). The solar energy plants must use the surfaces of buildings instead of occupying other green areas useful for agricultural activities. On this basis, we propose in this paper a demonstrative project for a village in Sardinia, consisting of photovoltaic collectors connected in a network, to provide electricity to homes and hydrogen for transport purposes

    An Energy Autonomous House Equipped with a Solar PV Hydrogen Conversion System

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    The use of RES in buildings is difficult for their random nature; therefore the plants using photovoltaic solar collectors must be connected to a power supply or interconnected with Energy accumulators if the building is isolated. The conversion of electricity into hydrogen technology is best suited to solve the problem and allows you to transfer the solar energy captured from day to night, from summer to winter. This paper presents the feasibility study for a house powered by PV cogeneration solar collectors that reverse the electricity on the control unit that you command by a PC to power the household, using a heat pump, an electrolytic cell for the production of hydrogen to accumulate; control units sorting to the utilities the electricity produced by the fuel cell. The following are presented: The Energy analysis of the building, the plant design, economic analysi

    Influence of body weight on reproductive activity in Sarda female lambs

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    One way to improve reproductive performance of ewes is through extending its lifetime productivity. Breeding ewe lambs is one method of improving the reproductive performance in the sheep. In order to produce an offspring when the ewe lamb is approximately 1 yr of age, the autumn-born ewe must obtain puberty before the autumn breeding season begins. Onset of puberty is determined by integration of both internal and external factors, which then enable the neuroendocrine or hormonal event occur (Shirley et al., 2001). Age, photoperiod and body weight are the principal factors influencing puberty. The age at onset of the reproductive activity in the sheep is different among the various breeds. In the Sarda lambs the age of the onset of puberty is about 7-8 months. However the animals that have this age don’t reach the puberty if photoperiod and body weight are not suitable. Both the female lambs born in October-November and in February reach puberty in the same subsequent autumn breeding season. This reproductive behaviour evidences that photoperiod plays an important role in the onset of puberty (Papachristoforou et al., 2000).The female lambs born in later spring uneasily reach puberty within the subsequent breeding season, although photoperiod is favourable. This retard in the onset of reproductive activity is due to the attainment of the body maturity only during subsequent long day period but they reach reproductive activity only during the autumn of the subsequent year (Foster et al., 1985). In fact, some authors suggested that besides photoperiod and age, attainment of the 60% of adult weight is essential for onset of puberty (Abecia et al., 2001). Indeed the undernourished animals delay puberty, in comparison to well nourished subjects (I’Anson et al., 1997). This behaviour is linked to the different LH pulse frequency: restricted diet lambs show one pulse per 4 hours, instead fed ad libitum subjects manifest four or five pulse per 4 hours (Ebling et al., 1990). The purpose of this investigation is to determine the onset of puberty and to research its linkage with body weight in Sarda female lambs during breeding season under natural condition

    Contractile reserve in systemic sclerosis patients as a major predictor of global cardiac impairment and exercise tolerance

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    Several studies have evidenced high prevalence of myocardial systolic and diastolic dysfunction among patients with systemic sclerosis (SSc). Exercise echocardiography has shown a diagnostic and prognostic role in identifying early left ventricular (LV) dysfunction in several myocardial pathological settings. The aim of our study was to evaluate early signs of LV impairment under exercise and their correlation to patient's exercise tolerance. Forty-five patients (age 60.4 ± 10.3 years) with SSc and 20 age and sex comparable controls were enrolled in the study. All patients underwent clinical evaluation, 2D echocardiography associated with Tissue Doppler and speckle tracking to evaluate LV deformation indexes, and an exercise echocardiography to evaluate left ventricle contractile reserve (LVCR) and exercise pulmonary pressures. Finally, a 6-minute walking test (6MWT) to evaluate exercise tolerance was also performed. Compared to controls, SSc patients showed an impaired diastolic function (E/E' 10.9 ± 3.7 vs 8.36 ± 2.01; p < 0.01) associated with larger left atrial dimensions (LAVI 28.4 ± 8.7 vs 19.3 ± 4.6 mL/m2; p < 0.01). During exercise echocardiography, a reduced global longitudinal strain at peak exercise (S-GLS) was highlighted compared to controls (15.7 ± 3.6 vs 18.2 ± 2.2; p = 0.001). A S-GLS cutoff <18 %, identified by ROC analysis, identified SSc patients with a reduced diastolic function, exercise tolerance at the 6MWT and higher pulmonary pressures. Our data show that in SSc patients a reduced LVCR characterizes the patients with a more extensive cardiovascular impairment in terms of LV diastolic function, pulmonary pressures and exercise tolerance. These data underline the importance of exercise echocardiography for the preclinical screening of the LV impairment in this population

    Evidence for preferences of Italian patients for physician attire

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    BACKGROUND: The relationship between patient and physician is a complex interaction that includes multiple factors. The objective of this study was to explore Italian patients' preferences regarding physician appearance. METHODS: A questionnaire was developed to survey patients in different medical and surgical settings; each subject was asked to choose one picture of either a male or female physician from a selection of different attires (professional, casual, surgical scrubs, trendy, and careless). Patients were also surveyed about issues such as the presence of a name tag, hair length, trousers on women, amount of makeup, presence of tattoos, and body piercing. Statistical analysis was performed using a Chi-square test. RESULTS: A total of 765 questionnaires (534 completed from patients waiting for an internal medicine visit and 231 for other subspecialties) were completed. The majority (45%) of patients preferred the gastroenterologist to wear a surgical scrub with a white coat. For the other specialists, patients accepted either scrubs or formal dress under a white coat (P ≤ 0.05), with a name tag. Trendy attire was preferred by nine patients (1.1%). The entire sample judged it inappropriate for clinicians to have long hair, visible tattoos, body piercing, and, for women, to wear trousers and use excessive makeup. CONCLUSION: This is the first study conducted in Italy regarding physician attire. As in other Western countries, Italian patients favor physicians in professional attire with a white coat. Wearing professional dress is part of "etiquette based medicine" and may favorably influence clinician-patient relationships and patient compliance.</br

    Efficacy of 1998 <i>vs</i> 2006 first-line antiretroviral regimens for HIV infection: an ordinary clinics retrospective investigation

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    Purpose: The evidence suggesting increased HAART efficacy over time comes from randomized trials or cohort studies. This retrospective multicenter survey aimed to assess the variation over time in the efficacy and tolerability of first-line HAART regimens in unselected patients treated in ordinary clinical settings. Methods: Retrospective analysis of data of all patients starting first-line HAART regimens in 1998 and 2006 at adhering centers in the Italian CISAI group. Results: For the 543 patients included, mean age was 39.1 ± 9.8y in 1998 and 41.0 ± 10.7y in 2006 (p=0.03), with a similar proportion of males. Baseline mean log10 HIV-RNA was 4.56 ± 0.97 copies/mL in 1998 vs 4.91 ± 0.96 copies/mL in 2006 (p&lt;0.001); baseline mean CD4 T-cell counts were 343 ± 314/mm3 in 1998 vs 244 ± 174/mm3 in 2006 (p&lt;0.001). The following outcomes were significantly improved at 48w in 2006: proportion with undetectable HIV-RNA (86.3% vs 58.0%; p&lt;0.001); mean increase in CD4 T-cells count (252 ± 225 vs 173 ± 246; p&lt;0.001); HAART modification (20.1% vs 29.2%; p=0.02); HAART interruption (7.3% vs 14.6%; p=0.01); proportion reporting optimal adherence (92.2% vs 82.7%, p=0.03). No differences were observed in the prevalence of grade 3-4 WHO toxicities (26.4% vs 26.6%; p=0.9). Multivariate logistic regression showed that being treated in 1998 remained an independent predictor of virological failure after several adjustments, including adherence. Conclusions: Our data from patients not included in clinical trials or cohort studies provide an additional line of evidence that the effectiveness of HAART significantly improved in 2006. Treated patients, however, were significantly older and more frequently late HIV presenters in 2006 than in 1998.</br
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