1,720,992 research outputs found
Pre-operational survey of a U mine near Val Vedello, Italy
No full textResults obtained from radiometric research carried out from 1980-81 in the region of U mines in the Val Vedello are provided. Data are presented on 222Rn, 226Ra and natural U concentrations in spring and surface waters. Concentrations were found to be relatively low. There is some increase in the vicinity of the exploratory U mine but this is, at least up to the present, only of a local character. Data are presented on external gamma exposure, 210Pb and 210Po in foodstuffs and in the urine of normal and exposed population as well as 226Ra in milk and vegetable samples. The aim of this study is to outline a preliminary map of natural radioactivity on the site before starting the mining activity. This will enable us later to detect changes caused by the U mining, milling and mill-tailing disposal operations
come trasformare un calcolatore tascabile MOS/LSI in un unità per collegamento in linea: parte 2
No full text..
Photovoltaic pumping station for fresh water supply
No full textThe Zambelli photovoltaic (pv) pumping station supplies a mountainous area of Lessinia in the North of Verona with drinking water.
The specific design of this self-operating plant is characterized by direct connections; this mean that it is without any intermediate battery storage, between the pv-generator and the two variable frequency inverters, which are served by two asynchrone motored piston pumps.
The storage is hydraulic and it is formed from the reservoir of Villa Ponti of Lessinia’s drinking-water network, of which Zambelli is a lifting station.
The completely automatic operation, which includes a Maximum power tracking, is assured by a process controller, this also provides data monitoring of the system.
Location of the Plant; Zambelli a town of Boscochiesanuova (VR)
Related peak power; 70 kWp
Managed by; AGSM - Veron
Evaluation of total dose received by Italian uranium miners
No full textIn Italy there is a programme, now in the research stage, which involves the future exploitation of two uranium mines. About one hundred and fifty workers are at present employed in these facilities. A health physics surveillance programme is under way and has been designed to fulfil the requirements expected during future exploitation of the two mines. A complete evaluation of the total dose (external + internal) received by the workers will be achieved using a formula to combine different sources of exposure in terms of a radioprotection standard. External dose is evaluated on the basis of individual TLD dosemeters, while evaluation of internal dose is mainly achieved by an environmental surveillance programme of radon daughter concentration in mine air. The external dose received by the workers is lower than 0.2 mSv per month and internal exposure is less than 6.4 x 10^-3 J.h.m.^-3.a^-1 (or, using the old units, 2 WLM per year)
Liver iron assessment in rats by using NMR: a simple statistical analysis on T2-maps
No full textLiver iron assessment is useful in diagnosis and staging of several iron-related pathologies. Several works were published on the use of MRI as means for non-invasive liver iron concentration (LIC) measurement. Even thought the transverse relaxation rate showed to be effective in iron assessment of aqueous iron solution, it is still difficult to use MRI in order to get a reliable in-vivo LIC evaluation. Previously observed uniform T2 distribution in iron-overloaded rat livers makes difficult to establish which is the “real T2” that has to be correlated with the LIC.
In our experimental model, iron overload was induced in thirty-one rats by feeding them a high iron-content diet.
After MRI measurements (carried out a 4.7T) LICs were evaluated by submitting a relatively large part of each rat liver to atomic absorption spectrometry (AAS). T2 maps of the rat livers were then calculated and regions of interest (ROIs) were drawn within the maps in order to cover the entire lobe used for AAS. In this way it was possible to correlate the “mean” iron concentration of the liver sample with various statistical parameters evaluated in the ROIs.
Results showed that when simple statistical parameters (such as mean and standard deviation) are combined together it is possible to get a better correlation (R=0.947) that would not be possible if they were considered separately. The possibility to extend this approach to human is discussed
Anaerobic digestion as a means of energy regeneration in sewage purification plant "Città di Verona"
No full textIn the article we report the results achieved in energy recovery at Verona wastewater treatmont plant. Such recovery is obtained through sludge anaerobic digestion and use of biogas in a cogeneration station (two groups, 500 kW of electric power and 700 kw of thermic power each). In 1985 20 million cubic meters of sewage were processed, 10,000 tons of dewatered sludge 23% were obtained, producing 4,200-4,500 m^3/day of biogas with an average methane concentration of 70%, 7,200-7,500 kwh/day of electric energy were produced.
Average specific biogas production was 17-22 l/people x day.
These values allowed a saving of 45% in electric energy used by utilities of wastewater treatment plant in 1985. Each kwh produced costed L 18.
Owing to the good results obtained in sludge processing, we are now considering the possibility to dispose of organic fraction of MSW through the same biologica process.
Therefore it follows that reutilization of power within municipal service permits the best economic exploitation and a high profitability of investments
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